feat: new alternate syntax and switch to black + isort (yeah, maybe not the best time, but that is done).

bonobo/__main__.py

@@ -1,4 +1,4 @@
 from bonobo.commands import entrypoint
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     entrypoint()

bonobo/_api.py

@@ -45,14 +45,17 @@ def run(graph, *, plugins=None, services=None, strategy=None):
     plugins = plugins or []
 
     from bonobo import settings
+
     settings.check()
 
     if not settings.QUIET.get():  # pragma: no cover
         if _is_interactive_console():
             import mondrian
+
             mondrian.setup(excepthook=True)
 
             from bonobo.plugins.console import ConsoleOutputPlugin
+
             if ConsoleOutputPlugin not in plugins:
                 plugins.append(ConsoleOutputPlugin)
 
@@ -61,20 +64,23 @@ def run(graph, *, plugins=None, services=None, strategy=None):
                 from bonobo.contrib.jupyter import JupyterOutputPlugin
             except ImportError:
                 import logging
+
                 logging.warning(
                     'Failed to load jupyter widget. Easiest way is to install the optional "jupyter" '
-                    'dependencies with «pip install bonobo[jupyter]», but you can also install a specific '
-                    'version by yourself.'
+                    "dependencies with «pip install bonobo[jupyter]», but you can also install a specific "
+                    "version by yourself."
                 )
             else:
                 if JupyterOutputPlugin not in plugins:
                     plugins.append(JupyterOutputPlugin)
 
     import logging
+
     logging.getLogger().setLevel(settings.LOGGING_LEVEL.get())
     strategy = create_strategy(strategy)
 
     from bonobo.util.errors import sweeten_errors
+
     with sweeten_errors():
         return strategy.execute(graph, plugins=plugins, services=services)
 
@@ -83,15 +89,15 @@ def _inspect_as_graph(graph):
     return graph._repr_dot_()
 
 
-_inspect_formats = {'graph': _inspect_as_graph}
+_inspect_formats = {"graph": _inspect_as_graph}
 
 
 @api.register_graph
 def inspect(graph, *, plugins=None, services=None, strategy=None, format):
     if not format in _inspect_formats:
         raise NotImplementedError(
-            'Output format {} not implemented. Choices are: {}.'.format(
-                format, ', '.join(sorted(_inspect_formats.keys()))
+            "Output format {} not implemented. Choices are: {}.".format(
+                format, ", ".join(sorted(_inspect_formats.keys()))
             )
         )
     print(_inspect_formats[format](graph))
@@ -160,20 +166,18 @@ api.register_group(
 )
 
 # registry
-api.register_group(
-    create_reader,
-    create_writer,
-)
+api.register_group(create_reader, create_writer)
 
 
 def _is_interactive_console():
     import sys
+
     return sys.stdout.isatty()
 
 
 def _is_jupyter_notebook():
     try:
-        return get_ipython().__class__.__name__ == 'ZMQInteractiveShell'
+        return get_ipython().__class__.__name__ == "ZMQInteractiveShell"
     except NameError:
         return False
 
@@ -182,7 +186,8 @@ def _is_jupyter_notebook():
 def get_examples_path(*pathsegments):
     import os
     import pathlib
-    return str(pathlib.Path(os.path.dirname(__file__), 'examples', *pathsegments))
+
+    return str(pathlib.Path(os.path.dirname(__file__), "examples", *pathsegments))
 
 
 @api.register

bonobo/_version.py

@@ -1 +1 @@
-__version__ = '0.6.2'
+__version__ = "0.6.2"

bonobo/commands/__init__.py

@@ -19,9 +19,9 @@ def entrypoint(args=None):
     logger.setLevel(settings.LOGGING_LEVEL.get())
 
     parser = argparse.ArgumentParser()
-    parser.add_argument('--debug', '-D', action='store_true')
+    parser.add_argument("--debug", "-D", action="store_true")
 
-    subparsers = parser.add_subparsers(dest='command')
+    subparsers = parser.add_subparsers(dest="command")
     subparsers.required = True
 
     commands = {}
@@ -39,23 +39,24 @@ def entrypoint(args=None):
                 # old school, function based.
                 commands[ext.name] = ext.plugin(parser)
         except Exception:
-            logger.exception('Error while loading command {}.'.format(ext.name))
+            logger.exception("Error while loading command {}.".format(ext.name))
 
     from stevedore import ExtensionManager
-    mgr = ExtensionManager(namespace='bonobo.commands')
+
+    mgr = ExtensionManager(namespace="bonobo.commands")
     mgr.map(register_extension)
 
     parsed_args = parser.parse_args(args).__dict__
 
-    if parsed_args.pop('debug', False):
+    if parsed_args.pop("debug", False):
         settings.DEBUG.set(True)
         settings.LOGGING_LEVEL.set(logging.DEBUG)
         logger.setLevel(settings.LOGGING_LEVEL.get())
 
-    logger.debug('Command: ' + parsed_args['command'] + ' Arguments: ' + repr(parsed_args))
+    logger.debug("Command: " + parsed_args["command"] + " Arguments: " + repr(parsed_args))
 
     # Get command handler, execute, rince.
-    command = commands[parsed_args.pop('command')]
+    command = commands[parsed_args.pop("command")]
     command(**parsed_args)
 
     return 0

bonobo/commands/base.py

@@ -33,7 +33,7 @@ class BaseCommand:
         """
         The actual logic of the command. Subclasses must implement this method.
         """
-        raise NotImplementedError('Subclasses of BaseCommand must provide a handle() method')
+        raise NotImplementedError("Subclasses of BaseCommand must provide a handle() method")
 
 
 class BaseGraphCommand(BaseCommand):
@@ -48,8 +48,8 @@ class BaseGraphCommand(BaseCommand):
     def add_arguments(self, parser):
         # target arguments (cannot provide both).
         source_group = parser.add_mutually_exclusive_group(required=self.required)
-        source_group.add_argument('file', nargs='?', type=str)
-        source_group.add_argument('-m', dest='mod', type=str)
+        source_group.add_argument("file", nargs="?", type=str)
+        source_group.add_argument("-m", dest="mod", type=str)
 
         # add arguments to enforce system environment.
         parser = get_argument_parser(parser)
@@ -66,7 +66,7 @@ class BaseGraphCommand(BaseCommand):
 
     def do_handle(self, graph, **options):
         if not self.handler:
-            raise RuntimeError('{} has no handler defined.'.format(get_name(self)))
+            raise RuntimeError("{} has no handler defined.".format(get_name(self)))
         return self.handler(graph, **options)
 
     @contextmanager
@@ -87,20 +87,20 @@ class BaseGraphCommand(BaseCommand):
                     sys.argv = [mod]
                     self._run_module(mod)
                 else:
-                    raise RuntimeError('No target provided.')
+                    raise RuntimeError("No target provided.")
             finally:
                 sys.argv = _argv
 
             if _graph is None:
-                raise RuntimeError('Could not find graph.')
+                raise RuntimeError("Could not find graph.")
 
             yield _graph, _graph_execution_options, options
 
     def _run_path(self, file):
-        return runpy.run_path(file, run_name='__main__')
+        return runpy.run_path(file, run_name="__main__")
 
     def _run_module(self, mod):
-        return runpy.run_module(mod, run_name='__main__')
+        return runpy.run_module(mod, run_name="__main__")
 
 
 @contextmanager

bonobo/commands/convert.py

@@ -6,82 +6,75 @@ from bonobo.util.resolvers import _resolve_options, _resolve_transformations
 
 class ConvertCommand(BaseCommand):
     def add_arguments(self, parser):
-        parser.add_argument('input_filename', help='Input filename.')
-        parser.add_argument('output_filename', help='Output filename.')
+        parser.add_argument("input_filename", help="Input filename.")
+        parser.add_argument("output_filename", help="Output filename.")
         parser.add_argument(
-            '--' + READER,
-            '-r',
-            help='Choose the reader factory if it cannot be detected from extension, or if detection is wrong.'
+            "--" + READER,
+            "-r",
+            help="Choose the reader factory if it cannot be detected from extension, or if detection is wrong.",
         )
         parser.add_argument(
-            '--' + WRITER,
-            '-w',
-            help=
-            'Choose the writer factory if it cannot be detected from extension, or if detection is wrong (use - for console pretty print).'
+            "--" + WRITER,
+            "-w",
+            help="Choose the writer factory if it cannot be detected from extension, or if detection is wrong (use - for console pretty print).",
+        )
+        parser.add_argument("--limit", "-l", type=int, help="Adds a Limit() after the reader instance.", default=None)
+        parser.add_argument(
+            "--transformation",
+            "-t",
+            dest="transformation",
+            action="append",
+            help="Add a transformation between input and output (can be used multiple times, order is preserved).",
         )
         parser.add_argument(
-            '--limit',
-            '-l',
-            type=int,
-            help='Adds a Limit() after the reader instance.',
-            default=None,
-        )
-        parser.add_argument(
-            '--transformation',
-            '-t',
-            dest='transformation',
-            action='append',
-            help='Add a transformation between input and output (can be used multiple times, order is preserved).',
-        )
-        parser.add_argument(
-            '--option',
-            '-O',
-            dest='option',
-            action='append',
+            "--option",
+            "-O",
+            dest="option",
+            action="append",
             help='Add a named option to both reader and writer factories (i.e. foo="bar").',
         )
         parser.add_argument(
-            '--' + READER + '-option',
-            '-' + READER[0].upper(),
-            dest=READER + '_option',
-            action='append',
-            help='Add a named option to the reader factory.',
+            "--" + READER + "-option",
+            "-" + READER[0].upper(),
+            dest=READER + "_option",
+            action="append",
+            help="Add a named option to the reader factory.",
         )
         parser.add_argument(
-            '--' + WRITER + '-option',
-            '-' + WRITER[0].upper(),
-            dest=WRITER + '_option',
-            action='append',
-            help='Add a named option to the writer factory.',
+            "--" + WRITER + "-option",
+            "-" + WRITER[0].upper(),
+            dest=WRITER + "_option",
+            action="append",
+            help="Add a named option to the writer factory.",
         )
 
     def handle(
-            self,
-            input_filename,
-            output_filename,
-            reader=None,
-            reader_option=None,
-            writer=None,
-            writer_option=None,
-            option=None,
-            limit=None,
-            transformation=None,
+        self,
+        input_filename,
+        output_filename,
+        reader=None,
+        reader_option=None,
+        writer=None,
+        writer_option=None,
+        option=None,
+        limit=None,
+        transformation=None,
     ):
         reader_factory = default_registry.get_reader_factory_for(input_filename, format=reader)
         reader_kwargs = _resolve_options((option or []) + (reader_option or []))
 
-        if output_filename == '-':
+        if output_filename == "-":
             writer_factory = bonobo.PrettyPrinter
             writer_args = ()
         else:
             writer_factory = default_registry.get_writer_factory_for(output_filename, format=writer)
-            writer_args = (output_filename, )
+            writer_args = (output_filename,)
         writer_kwargs = _resolve_options((option or []) + (writer_option or []))
 
         transformations = ()
 
         if limit:
-            transformations += (bonobo.Limit(limit), )
+            transformations += (bonobo.Limit(limit),)
 
         transformations += _resolve_transformations(transformation)
 
@@ -92,8 +85,4 @@ class ConvertCommand(BaseCommand):
             writer_factory(*writer_args, **writer_kwargs),
         )
 
-        return bonobo.run(
-            graph, services={
-                'fs': bonobo.open_fs(),
-            }
-        )
+        return bonobo.run(graph, services={"fs": bonobo.open_fs()})

bonobo/commands/download.py

@@ -6,28 +6,28 @@ import requests
 import bonobo
 from bonobo.commands import BaseCommand
 
-EXAMPLES_BASE_URL = 'https://raw.githubusercontent.com/python-bonobo/bonobo/master/bonobo/examples/'
+EXAMPLES_BASE_URL = "https://raw.githubusercontent.com/python-bonobo/bonobo/master/bonobo/examples/"
 """The URL to our git repository, in raw mode."""
 
 
 class DownloadCommand(BaseCommand):
     def handle(self, *, path, **options):
-        if not path.startswith('examples'):
-            raise ValueError('Download command currently supports examples only')
-        examples_path = re.sub('^examples/', '', path)
+        if not path.startswith("examples"):
+            raise ValueError("Download command currently supports examples only")
+        examples_path = re.sub("^examples/", "", path)
         output_path = bonobo.get_examples_path(examples_path)
-        with _open_url(EXAMPLES_BASE_URL + examples_path) as response, open(output_path, 'wb') as fout:
+        with _open_url(EXAMPLES_BASE_URL + examples_path) as response, open(output_path, "wb") as fout:
             for chunk in response.iter_content(io.DEFAULT_BUFFER_SIZE):
                 fout.write(chunk)
-        self.logger.info('Download saved to {}'.format(output_path))
+        self.logger.info("Download saved to {}".format(output_path))
 
     def add_arguments(self, parser):
-        parser.add_argument('path', help='The relative path of the thing to download.')
+        parser.add_argument("path", help="The relative path of the thing to download.")
 
 
 def _open_url(url):
     """Open a HTTP connection to the URL and return a file-like object."""
     response = requests.get(url, stream=True)
     if response.status_code != 200:
-        raise IOError('Unable to download {}, HTTP {}'.format(url, response.status_code))
+        raise IOError("Unable to download {}, HTTP {}".format(url, response.status_code))
     return response

bonobo/commands/examples.py

@@ -1,23 +1,23 @@
 from bonobo.commands import BaseCommand
 
 all_examples = (
-    'clock',
-    'datasets',
-    'environ',
-    'files.csv_handlers',
-    'files.json_handlers',
-    'files.pickle_handlers',
-    'files.text_handlers',
-    'types',
+    "clock",
+    "datasets",
+    "environ",
+    "files.csv_handlers",
+    "files.json_handlers",
+    "files.pickle_handlers",
+    "files.text_handlers",
+    "types",
 )
 
 
 class ExamplesCommand(BaseCommand):
     def handle(self):
-        print('You can run the following examples:')
+        print("You can run the following examples:")
         print()
         for example in all_examples:
-            print('  $ python -m bonobo.examples.{}'.format(example))
+            print("  $ python -m bonobo.examples.{}".format(example))
         print()
 
     def add_arguments(self, parser):

bonobo/commands/init.py

@@ -6,67 +6,67 @@ from bonobo.commands import BaseCommand
 
 
 class InitCommand(BaseCommand):
-    TEMPLATES = {'bare', 'default'}
-    TEMPLATES_PATH = os.path.join(os.path.dirname(__file__), 'templates')
+    TEMPLATES = {"bare", "default"}
+    TEMPLATES_PATH = os.path.join(os.path.dirname(__file__), "templates")
 
     def add_arguments(self, parser):
-        parser.add_argument('filename')
-        parser.add_argument('--force', '-f', default=False, action='store_true')
+        parser.add_argument("filename")
+        parser.add_argument("--force", "-f", default=False, action="store_true")
 
         target_group = parser.add_mutually_exclusive_group(required=False)
-        target_group.add_argument('--template', '-t', choices=self.TEMPLATES, default='default')
-        target_group.add_argument('--package', '-p', action='store_true', default=False)
+        target_group.add_argument("--template", "-t", choices=self.TEMPLATES, default="default")
+        target_group.add_argument("--package", "-p", action="store_true", default=False)
 
     def create_file_from_template(self, *, template, filename):
         template_name = template
         name, ext = os.path.splitext(filename)
-        if ext != '.py':
+        if ext != ".py":
             raise ValueError('Filenames should end with ".py".')
 
         loader = FileSystemLoader(self.TEMPLATES_PATH)
         env = Environment(loader=loader)
-        template = env.get_template(template_name + '.py-tpl')
+        template = env.get_template(template_name + ".py-tpl")
 
-        with open(filename, 'w+') as f:
+        with open(filename, "w+") as f:
             f.write(template.render(name=name))
 
-        self.logger.info('Generated {} using template {!r}.'.format(filename, template_name))
+        self.logger.info("Generated {} using template {!r}.".format(filename, template_name))
 
     def create_package(self, *, filename):
         name, ext = os.path.splitext(filename)
-        if ext != '':
-            raise ValueError('Package names should not have an extension.')
+        if ext != "":
+            raise ValueError("Package names should not have an extension.")
 
         try:
             import medikit.commands
         except ImportError as exc:
             raise ImportError(
-                'To initialize a package, you need to install medikit (pip install --upgrade medikit).'
+                "To initialize a package, you need to install medikit (pip install --upgrade medikit)."
             ) from exc
 
         package_name = os.path.basename(filename)
         medikit.commands.handle_init(
-            os.path.join(os.getcwd(), filename, 'Projectfile'), name=package_name, requirements=['bonobo']
+            os.path.join(os.getcwd(), filename, "Projectfile"), name=package_name, requirements=["bonobo"]
         )
 
         self.logger.info('Generated "{}" package with medikit.'.format(package_name))
-        self.create_file_from_template(template='default', filename=os.path.join(filename, package_name, '__main__.py'))
+        self.create_file_from_template(template="default", filename=os.path.join(filename, package_name, "__main__.py"))
 
         print('Your "{}" package has been created.'.format(package_name))
         print()
-        print('Install it...')
+        print("Install it...")
         print()
-        print('    pip install --editable {}'.format(filename))
+        print("    pip install --editable {}".format(filename))
         print()
-        print('Then maybe run the example...')
+        print("Then maybe run the example...")
         print()
-        print('    python -m {}'.format(package_name))
+        print("    python -m {}".format(package_name))
         print()
-        print('Enjoy!')
+        print("Enjoy!")
 
     def handle(self, *, template, filename, package=False, force=False):
         if os.path.exists(filename) and not force:
-            raise FileExistsError('Target filename already exists, use --force to override.')
+            raise FileExistsError("Target filename already exists, use --force to override.")
 
         if package:
             self.create_package(filename=filename)

bonobo/commands/inspect.py

@@ -7,9 +7,9 @@ class InspectCommand(BaseGraphCommand):
 
     def add_arguments(self, parser):
         super(InspectCommand, self).add_arguments(parser)
-        parser.add_argument('--graph', '-g', dest='format', action='store_const', const='graph')
+        parser.add_argument("--graph", "-g", dest="format", action="store_const", const="graph")
 
     def parse_options(self, **options):
-        if not options.get('format'):
-            raise RuntimeError('You must provide a format (try --graph).')
+        if not options.get("format"):
+            raise RuntimeError("You must provide a format (try --graph).")
         return options

bonobo/commands/run.py

@@ -12,13 +12,14 @@ class RunCommand(BaseGraphCommand):
         super(RunCommand, self).add_arguments(parser)
 
         verbosity_group = parser.add_mutually_exclusive_group()
-        verbosity_group.add_argument('--quiet', '-q', action='store_true')
-        verbosity_group.add_argument('--verbose', '-v', action='store_true')
+        verbosity_group.add_argument("--quiet", "-q", action="store_true")
+        verbosity_group.add_argument("--verbose", "-v", action="store_true")
 
-        parser.add_argument('--install', '-I', action='store_true')
+        parser.add_argument("--install", "-I", action="store_true")
 
     def parse_options(self, *, quiet=False, verbose=False, install=False, **options):
         from bonobo import settings
+
         settings.QUIET.set_if_true(quiet)
         settings.DEBUG.set_if_true(verbose)
         self.install = install
@@ -28,9 +29,9 @@ class RunCommand(BaseGraphCommand):
         # add install logic
         if self.install:
             if os.path.isdir(file):
-                requirements = os.path.join(file, 'requirements.txt')
+                requirements = os.path.join(file, "requirements.txt")
             else:
-                requirements = os.path.join(os.path.dirname(file), 'requirements.txt')
+                requirements = os.path.join(os.path.dirname(file), "requirements.txt")
             _install_requirements(requirements)
 
         return super()._run_path(file)
@@ -38,7 +39,7 @@ class RunCommand(BaseGraphCommand):
     def _run_module(self, mod):
         # install not implemented for a module, not sure it even make sense.
         if self.install:
-            raise RuntimeError('--install behaviour when running a module is not defined.')
+            raise RuntimeError("--install behaviour when running a module is not defined.")
 
         return super()._run_module(mod)
 
@@ -59,10 +60,11 @@ def _install_requirements(requirements):
     import importlib
     import pip
 
-    pip.main(['install', '-r', requirements])
+    pip.main(["install", "-r", requirements])
     # Some shenanigans to be sure everything is importable after this, especially .egg-link files which
     # are referenced in *.pth files and apparently loaded by site.py at some magic bootstrap moment of the
     # python interpreter.
     pip.utils.pkg_resources = importlib.reload(pip.utils.pkg_resources)
     import site
+
     importlib.reload(site)

bonobo/commands/templates/bare.py-tpl

@@ -3,6 +3,7 @@ import bonobo
 
 def get_graph(**options):
     graph = bonobo.Graph()
+    graph.get_cursor() >> ...
     return graph
 
 

bonobo/commands/templates/default.py-tpl

@@ -27,7 +27,7 @@ def get_graph(**options):
 
     """
     graph = bonobo.Graph()
-    graph.add_chain(extract, transform, load)
+    graph.get_cursor() >> extract >> transform >> load
 
     return graph
 

bonobo/commands/version.py

@@ -9,15 +9,15 @@ def get_versions(*, all=False, quiet=None):
 
     if all:
         for name in sorted(bonobo_packages):
-            if name != 'bonobo':
+            if name != "bonobo":
                 try:
-                    mod = __import__(name.replace('-', '_'))
+                    mod = __import__(name.replace("-", "_"))
                     try:
                         yield _format_version(mod, name=name, quiet=quiet)
                     except Exception as exc:
-                        yield '{} ({})'.format(name, exc)
+                        yield "{} ({})".format(name, exc)
                 except ImportError as exc:
-                    yield '{} is not importable ({}).'.format(name, exc)
+                    yield "{} is not importable ({}).".format(name, exc)
 
 
 class VersionCommand(BaseCommand):
@@ -26,23 +26,24 @@ class VersionCommand(BaseCommand):
             print(line)
 
     def add_arguments(self, parser):
-        parser.add_argument('--all', '-a', action='store_true')
-        parser.add_argument('--quiet', '-q', action='count')
+        parser.add_argument("--all", "-a", action="store_true")
+        parser.add_argument("--quiet", "-q", action="count")
 
 
 def _format_version(mod, *, name=None, quiet=False):
     from bonobo.util.pkgs import bonobo_packages
+
     args = {
-        'name': name or mod.__name__,
-        'version': mod.__version__,
-        'location': bonobo_packages[name or mod.__name__].location
+        "name": name or mod.__name__,
+        "version": mod.__version__,
+        "location": bonobo_packages[name or mod.__name__].location,
     }
 
     if not quiet:
-        return '{name} v.{version} (in {location})'.format(**args)
+        return "{name} v.{version} (in {location})".format(**args)
     if quiet < 2:
-        return '{name} {version}'.format(**args)
+        return "{name} {version}".format(**args)
     if quiet < 3:
-        return '{version}'.format(**args)
+        return "{version}".format(**args)
 
-    raise RuntimeError('Hard to be so quiet...')
+    raise RuntimeError("Hard to be so quiet...")

bonobo/config/__init__.py

@@ -11,23 +11,23 @@ from bonobo.config.processors import ContextProcessor, use_context, use_context_
 from bonobo.config.services import Container, Exclusive, Service, use, create_container
 from bonobo.util import deprecated_alias
 
-requires = deprecated_alias('requires', use)
+requires = deprecated_alias("requires", use)
 
 # Bonobo's Config API
 __all__ = [
-    'Configurable',
-    'Container',
-    'ContextProcessor',
-    'Exclusive',
-    'Method',
-    'Option',
-    'Service',
-    'create_container',
-    'requires',
-    'transformation_factory',
-    'use',
-    'use_context',
-    'use_context_processor',
-    'use_no_input',
-    'use_raw_input',
+    "Configurable",
+    "Container",
+    "ContextProcessor",
+    "Exclusive",
+    "Method",
+    "Option",
+    "Service",
+    "create_container",
+    "requires",
+    "transformation_factory",
+    "use",
+    "use_context",
+    "use_context_processor",
+    "use_no_input",
+    "use_raw_input",
 ]

bonobo/config/configurables.py

@@ -1,9 +1,7 @@
 from bonobo.errors import AbstractError
 from bonobo.util import get_name, iscontextprocessor, isoption, sortedlist
 
-__all__ = [
-    'Configurable',
-]
+__all__ = ["Configurable"]
 
 get_creation_counter = lambda v: v._creation_counter
 
@@ -42,12 +40,12 @@ class ConfigurableMeta(type):
         for _positional, _counter, _name, _value in cls.__options:
             _param = _name
             if _value.type:
-                _param = get_name(_value.type) + ' ' + _param
+                _param = get_name(_value.type) + " " + _param
 
-            prefix = ':param {}: '.format(_param)
-            for lineno, line in enumerate((_value.__doc__ or '').split('\n')):
-                _options_doc.append((' ' * len(prefix) if lineno else prefix) + line)
-        cls.__doc__ = '\n\n'.join(map(str.strip, filter(None, (cls.__doc__, '\n'.join(_options_doc)))))
+            prefix = ":param {}: ".format(_param)
+            for lineno, line in enumerate((_value.__doc__ or "").split("\n")):
+                _options_doc.append((" " * len(prefix) if lineno else prefix) + line)
+        cls.__doc__ = "\n\n".join(map(str.strip, filter(None, (cls.__doc__, "\n".join(_options_doc)))))
 
     @property
     def __options__(cls):
@@ -64,10 +62,7 @@ class ConfigurableMeta(type):
         return cls.__processors_cache
 
     def __repr__(self):
-        return ' '.join((
-            '<Configurable',
-            super(ConfigurableMeta, self).__repr__().split(' ', 1)[1],
-        ))
+        return " ".join(("<Configurable", super(ConfigurableMeta, self).__repr__().split(" ", 1)[1]))
 
 
 try:
@@ -154,9 +149,11 @@ class Configurable(metaclass=ConfigurableMeta):
         extraneous = set(kwargs.keys()) - (set(next(zip(*options))) if len(options) else set())
         if len(extraneous):
             raise TypeError(
-                '{}() got {} unexpected option{}: {}.'.format(
-                    cls.__name__, len(extraneous), 's'
-                    if len(extraneous) > 1 else '', ', '.join(map(repr, sorted(extraneous)))
+                "{}() got {} unexpected option{}: {}.".format(
+                    cls.__name__,
+                    len(extraneous),
+                    "s" if len(extraneous) > 1 else "",
+                    ", ".join(map(repr, sorted(extraneous))),
                 )
             )
 
@@ -165,9 +162,11 @@ class Configurable(metaclass=ConfigurableMeta):
         if len(missing):
             if _final:
                 raise TypeError(
-                    '{}() missing {} required option{}: {}.'.format(
-                        cls.__name__, len(missing), 's'
-                        if len(missing) > 1 else '', ', '.join(map(repr, sorted(missing)))
+                    "{}() missing {} required option{}: {}.".format(
+                        cls.__name__,
+                        len(missing),
+                        "s" if len(missing) > 1 else "",
+                        ", ".join(map(repr, sorted(missing))),
                     )
                 )
             return PartiallyConfigured(cls, *args, **kwargs)
@@ -196,7 +195,7 @@ class Configurable(metaclass=ConfigurableMeta):
                 break
 
             if name in self._options_values:
-                raise ValueError('Already got a value for option {}'.format(name))
+                raise ValueError("Already got a value for option {}".format(name))
 
             setattr(self, name, args[position])
             position += 1

bonobo/config/functools.py

@@ -6,8 +6,8 @@ def transformation_factory(f):
     @functools.wraps(f)
     def _transformation_factory(*args, **kwargs):
         retval = f(*args, **kwargs)
-        retval.__name__ = f.__name__ + '({})'.format(
-            ', '.join(itertools.chain(map(repr, args), ('{}={!r}'.format(k, v) for k, v in kwargs.items())))
+        retval.__name__ = f.__name__ + "({})".format(
+            ", ".join(itertools.chain(map(repr, args), ("{}={!r}".format(k, v) for k, v in kwargs.items())))
         )
         return retval
 

bonobo/config/options.py

@@ -66,9 +66,9 @@ class Option:
         # Docstring formating
         self.__doc__ = __doc__ or None
         if self.__doc__:
-            self.__doc__ = textwrap.dedent(self.__doc__.strip('\n')).strip()
+            self.__doc__ = textwrap.dedent(self.__doc__.strip("\n")).strip()
             if default:
-                self.__doc__ += '\n\nDefault: {!r}'.format(default)
+                self.__doc__ += "\n\nDefault: {!r}".format(default)
 
         # This hack is necessary for python3.5
         self._creation_counter = Option._creation_counter
@@ -88,13 +88,13 @@ class Option:
         inst._options_values[self.name] = self.clean(value)
 
     def __repr__(self):
-        return '<{positional}{typename} {type}{name} default={default!r}{required}>'.format(
+        return "<{positional}{typename} {type}{name} default={default!r}{required}>".format(
             typename=type(self).__name__,
-            type='({})'.format(self.type) if istype(self.type) else '',
+            type="({})".format(self.type) if istype(self.type) else "",
             name=self.name,
-            positional='*' if self.positional else '**',
+            positional="*" if self.positional else "**",
             default=self.default,
-            required=' (required)' if self.required else '',
+            required=" (required)" if self.required else "",
         )
 
     def clean(self, value):
@@ -106,15 +106,16 @@ class Option:
 
 class RemovedOption(Option):
     def __init__(self, *args, value, **kwargs):
-        kwargs['required'] = False
+        kwargs["required"] = False
         super(RemovedOption, self).__init__(*args, **kwargs)
         self.value = value
 
     def clean(self, value):
         if value != self.value:
             raise ValueError(
-                'Removed options cannot change value, {!r} must now be {!r} (and you should remove setting the value explicitely, as it is deprecated and will be removed quite soon.'.
-                format(self.name, self.value)
+                "Removed options cannot change value, {!r} must now be {!r} (and you should remove setting the value explicitely, as it is deprecated and will be removed quite soon.".format(
+                    self.name, self.value
+                )
             )
         return self.value
 
@@ -129,12 +130,12 @@ class RenamedOption(Option):
 
     def __get__(self, instance, owner):
         raise ValueError(
-            'Trying to get value from renamed option {}, try getting {} instead.'.format(self.name, self.target)
+            "Trying to get value from renamed option {}, try getting {} instead.".format(self.name, self.target)
         )
 
     def clean(self, value):
         raise ValueError(
-            'Trying to set value of renamed option {}, try setting {} instead.'.format(self.name, self.target)
+            "Trying to set value of renamed option {}, try setting {} instead.".format(self.name, self.target)
         )
 
 
@@ -182,7 +183,7 @@ class Method(Option):
         # If a callable is provided as default, then use self as if it was used as a decorator
         if default is not None:
             if not callable(default):
-                raise ValueError('Method defaults should be callable, if provided.')
+                raise ValueError("Method defaults should be callable, if provided.")
             self(default)
 
     def __get__(self, inst, type_):
@@ -194,17 +195,15 @@ class Method(Option):
     def __set__(self, inst, value):
         if not callable(value):
             raise TypeError(
-                'Option {!r} ({}) is expecting a callable value, got {!r} object: {!r}.'.format(
-                    self.name,
-                    type(self).__name__,
-                    type(value).__name__, value
+                "Option {!r} ({}) is expecting a callable value, got {!r} object: {!r}.".format(
+                    self.name, type(self).__name__, type(value).__name__, value
                 )
             )
         inst._options_values[self.name] = self.type(value) if self.type else value
 
     def __call__(self, impl):
         if self.default:
-            raise RuntimeError('Can only be used once as a decorator.')
+            raise RuntimeError("Can only be used once as a decorator.")
         self.default = impl
         self.required = False
         return self

bonobo/config/processors.py

@@ -53,7 +53,7 @@ class ContextProcessor(Option):
         self.name = self.__name__
 
     def __repr__(self):
-        return repr(self.func).replace('<function', '<{}'.format(type(self).__name__))
+        return repr(self.func).replace("<function", "<{}".format(type(self).__name__))
 
     def __call__(self, *args, **kwargs):
         return self.func(*args, **kwargs)
@@ -74,7 +74,7 @@ class ContextCurrifier:
         self.wrapped = wrapped
         self.args = args
         self.kwargs = kwargs
-        self.format = getattr(wrapped, '__input_format__', _args)
+        self.format = getattr(wrapped, "__input_format__", _args)
         self._stack, self._stack_values = None, None
 
     def __iter__(self):
@@ -91,30 +91,32 @@ class ContextCurrifier:
             return bind(*self.args, _input, **self.kwargs)
         if self.format is _none:
             return bind(*self.args, **self.kwargs)
-        raise NotImplementedError('Invalid format {!r}.'.format(self.format))
+        raise NotImplementedError("Invalid format {!r}.".format(self.format))
 
     def __call__(self, _input):
         if not callable(self.wrapped):
             if isinstance(self.wrapped, Iterable):
                 return self.__iter__()
-            raise UnrecoverableTypeError('Uncallable node {}'.format(self.wrapped))
+            raise UnrecoverableTypeError("Uncallable node {}".format(self.wrapped))
         try:
             bound = self._bind(_input)
         except TypeError as exc:
-            raise UnrecoverableTypeError((
-                'Input of {wrapped!r} does not bind to the node signature.\n'
-                'Args: {args}\n'
-                'Input: {input}\n'
-                'Kwargs: {kwargs}\n'
-                'Signature: {sig}'
-            ).format(
-                wrapped=self.wrapped, args=self.args, input=_input, kwargs=self.kwargs, sig=signature(self.wrapped)
-            )) from exc
+            raise UnrecoverableTypeError(
+                (
+                    "Input of {wrapped!r} does not bind to the node signature.\n"
+                    "Args: {args}\n"
+                    "Input: {input}\n"
+                    "Kwargs: {kwargs}\n"
+                    "Signature: {sig}"
+                ).format(
+                    wrapped=self.wrapped, args=self.args, input=_input, kwargs=self.kwargs, sig=signature(self.wrapped)
+                )
+            ) from exc
         return self.wrapped(*bound.args, **bound.kwargs)
 
     def setup(self, *context):
         if self._stack is not None:
-            raise RuntimeError('Cannot setup context currification twice.')
+            raise RuntimeError("Cannot setup context currification twice.")
 
         self._stack, self._stack_values = list(), list()
         for processor in resolve_processors(self.wrapped):
@@ -136,7 +138,7 @@ class ContextCurrifier:
                 pass
             else:
                 # No error ? We should have had StopIteration ...
-                raise RuntimeError('Context processors should not yield more than once.')
+                raise RuntimeError("Context processors should not yield more than once.")
         self._stack, self._stack_values = None, None
 
     @contextmanager
@@ -164,7 +166,7 @@ def resolve_processors(mixed):
         yield from ()
 
 
-get_context_processors = deprecated_alias('get_context_processors', resolve_processors)
+get_context_processors = deprecated_alias("get_context_processors", resolve_processors)
 
 
 def use_context(f):
@@ -192,11 +194,11 @@ def use_context_processor(context_processor):
 def _use_input_format(input_format):
     if input_format not in INPUT_FORMATS:
         raise ValueError(
-            'Invalid input format {!r}. Choices: {}'.format(input_format, ', '.join(sorted(INPUT_FORMATS)))
+            "Invalid input format {!r}. Choices: {}".format(input_format, ", ".join(sorted(INPUT_FORMATS)))
         )
 
     def _set_input_format(f):
-        setattr(f, '__input_format__', input_format)
+        setattr(f, "__input_format__", input_format)
         return f
 
     return _set_input_format

bonobo/config/services.py

@@ -11,7 +11,7 @@ _service_name_re = re.compile(r"^[^\d\W]\w*(:?\.[^\d\W]\w*)*$", re.UNICODE)
 
 def validate_service_name(name):
     if not _service_name_re.match(name):
-        raise ValueError('Invalid service name {!r}.'.format(name))
+        raise ValueError("Invalid service name {!r}.".format(name))
     return name
 
 
@@ -66,7 +66,7 @@ class Service(Option):
 class Container(dict):
     def __new__(cls, *args, **kwargs):
         if len(args) == 1:
-            assert not len(kwargs), 'only one usage at a time, my dear.'
+            assert not len(kwargs), "only one usage at a time, my dear."
             if not (args[0]):
                 return super().__new__(cls)
             if isinstance(args[0], cls):
@@ -86,7 +86,7 @@ class Container(dict):
             if default:
                 return default
             raise MissingServiceImplementationError(
-                'Cannot resolve service {!r} using provided service collection.'.format(name)
+                "Cannot resolve service {!r} using provided service collection.".format(name)
             )
         value = super().get(name)
         # XXX this is not documented and can lead to errors.
@@ -108,13 +108,15 @@ def create_container(services=None, factory=Container):
     """
     container = factory(services) if services else factory()
 
-    if not 'fs' in container:
+    if not "fs" in container:
         import bonobo
-        container.setdefault('fs', bonobo.open_fs())
 
-    if not 'http' in container:
+        container.setdefault("fs", bonobo.open_fs())
+
+    if not "http" in container:
         import requests
-        container.setdefault('http', requests)
+
+        container.setdefault("http", requests)
 
     return container
 
@@ -137,6 +139,7 @@ class Exclusive(ContextDecorator):
     ensure that.
 
     """
+
     _locks = {}
 
     def __init__(self, wrapped):

bonobo/constants.py

@@ -23,8 +23,8 @@
 from bonobo.structs.tokens import Token
 from bonobo.util.envelopes import UnchangedEnvelope
 
-BEGIN = Token('Begin')
-END = Token('End')
+BEGIN = Token("Begin")
+END = Token("End")
 
 NOT_MODIFIED = UnchangedEnvelope()
 

bonobo/contrib/django/__init__.py

@@ -9,7 +9,4 @@ This module contains all tools for Bonobo and Django to interract nicely.
 from .utils import create_or_update
 from .commands import ETLCommand
 
-__all__ = [
-    'ETLCommand',
-    'create_or_update',
-]
+__all__ = ["ETLCommand", "create_or_update"]

bonobo/contrib/django/commands.py

@@ -35,7 +35,7 @@ class ETLCommand(BaseCommand):
 
     def get_graph(self, *args, **options):
         def not_implemented():
-            raise NotImplementedError('You must implement {}.get_graph() method.'.format(self))
+            raise NotImplementedError("You must implement {}.get_graph() method.".format(self))
 
         return bonobo.Graph(not_implemented)
 
@@ -56,14 +56,14 @@ class ETLCommand(BaseCommand):
             graph_coll = self.get_graph(*args, **options)
 
             if not isinstance(graph_coll, GeneratorType):
-                graph_coll = (graph_coll, )
+                graph_coll = (graph_coll,)
 
             for i, graph in enumerate(graph_coll):
-                assert isinstance(graph, bonobo.Graph), 'Invalid graph provided.'
-                print(term.lightwhite('{}. {}'.format(i + 1, graph.name)))
+                assert isinstance(graph, bonobo.Graph), "Invalid graph provided."
+                print(term.lightwhite("{}. {}".format(i + 1, graph.name)))
                 result = bonobo.run(graph, services=services, strategy=strategy)
                 results.append(result)
-                print(term.lightblack(' ... return value: ' + str(result)))
+                print(term.lightblack(" ... return value: " + str(result)))
                 print()
 
         return results
@@ -71,9 +71,9 @@ class ETLCommand(BaseCommand):
     def handle(self, *args, **options):
         _stdout_backup, _stderr_backup = self.stdout, self.stderr
 
-        self.stdout = OutputWrapper(ConsoleOutputPlugin._stdout, ending=CLEAR_EOL + '\n')
-        self.stderr = OutputWrapper(ConsoleOutputPlugin._stderr, ending=CLEAR_EOL + '\n')
-        self.stderr.style_func = lambda x: Fore.LIGHTRED_EX + Back.RED + '!' + Style.RESET_ALL + ' ' + x
+        self.stdout = OutputWrapper(ConsoleOutputPlugin._stdout, ending=CLEAR_EOL + "\n")
+        self.stderr = OutputWrapper(ConsoleOutputPlugin._stderr, ending=CLEAR_EOL + "\n")
+        self.stderr.style_func = lambda x: Fore.LIGHTRED_EX + Back.RED + "!" + Style.RESET_ALL + " " + x
 
         self.run(*args, **kwargs)
 

bonobo/contrib/google/__init__.py

@@ -9,8 +9,8 @@ from oauth2client import client, tools
 from oauth2client.file import Storage
 from oauth2client.tools import argparser
 
-HOME_DIR = os.path.expanduser('~')
-GOOGLE_SECRETS = os.path.join(HOME_DIR, '.cache/secrets/client_secrets.json')
+HOME_DIR = os.path.expanduser("~")
+GOOGLE_SECRETS = os.path.join(HOME_DIR, ".cache/secrets/client_secrets.json")
 
 
 def get_credentials(*, scopes):
@@ -22,10 +22,10 @@ def get_credentials(*, scopes):
     Returns:
         Credentials, the obtained credential.
     """
-    credential_dir = os.path.join(HOME_DIR, '.cache', __package__, 'credentials')
+    credential_dir = os.path.join(HOME_DIR, ".cache", __package__, "credentials")
     if not os.path.exists(credential_dir):
         os.makedirs(credential_dir)
-    credential_path = os.path.join(credential_dir, 'googleapis.json')
+    credential_path = os.path.join(credential_dir, "googleapis.json")
 
     store = Storage(credential_path)
     credentials = store.get()
@@ -34,22 +34,22 @@ def get_credentials(*, scopes):
     # kw: "incremental scopes"
     if not credentials or credentials.invalid or not credentials.has_scopes(scopes):
         flow = client.flow_from_clientsecrets(GOOGLE_SECRETS, scopes)
-        flow.user_agent = 'Bonobo ETL (https://www.bonobo-project.org/)'
-        flags = argparser.parse_args(['--noauth_local_webserver'])
+        flow.user_agent = "Bonobo ETL (https://www.bonobo-project.org/)"
+        flags = argparser.parse_args(["--noauth_local_webserver"])
         credentials = tools.run_flow(flow, store, flags)
-        print('Storing credentials to ' + credential_path)
+        print("Storing credentials to " + credential_path)
     return credentials
 
 
-def get_google_spreadsheets_api_client(scopes=('https://www.googleapis.com/auth/spreadsheets', )):
+def get_google_spreadsheets_api_client(scopes=("https://www.googleapis.com/auth/spreadsheets",)):
     credentials = get_credentials(scopes=scopes)
     http = credentials.authorize(httplib2.Http())
-    discoveryUrl = 'https://sheets.googleapis.com/$discovery/rest?version=v4'
-    return discovery.build('sheets', 'v4', http=http, discoveryServiceUrl=discoveryUrl, cache_discovery=False)
+    discoveryUrl = "https://sheets.googleapis.com/$discovery/rest?version=v4"
+    return discovery.build("sheets", "v4", http=http, discoveryServiceUrl=discoveryUrl, cache_discovery=False)
 
 
-def get_google_people_api_client(scopes=('https://www.googleapis.com/auth/contacts', )):
+def get_google_people_api_client(scopes=("https://www.googleapis.com/auth/contacts",)):
     credentials = get_credentials(scopes=scopes)
     http = credentials.authorize(httplib2.Http())
-    discoveryUrl = 'https://people.googleapis.com/$discovery/rest?version=v1'
-    return discovery.build('people', 'v1', http=http, discoveryServiceUrl=discoveryUrl, cache_discovery=False)
+    discoveryUrl = "https://people.googleapis.com/$discovery/rest?version=v1"
+    return discovery.build("people", "v1", http=http, discoveryServiceUrl=discoveryUrl, cache_discovery=False)

bonobo/contrib/jupyter/__init__.py

@@ -2,9 +2,7 @@ from bonobo.plugins.jupyter import JupyterOutputPlugin
 
 
 def _jupyter_nbextension_paths():
-    return [{'section': 'notebook', 'src': 'static', 'dest': 'bonobo-jupyter', 'require': 'bonobo-jupyter/extension'}]
+    return [{"section": "notebook", "src": "static", "dest": "bonobo-jupyter", "require": "bonobo-jupyter/extension"}]
 
 
-__all__ = [
-    'JupyterOutputPlugin',
-]
+__all__ = ["JupyterOutputPlugin"]

bonobo/contrib/jupyter/widget.py

@@ -2,10 +2,10 @@ import ipywidgets as widgets
 from traitlets import List, Unicode
 
 
-@widgets.register('bonobo-widget.bonobo')
+@widgets.register("bonobo-widget.bonobo")
 class BonoboWidget(widgets.DOMWidget):
-    _view_name = Unicode('BonoboView').tag(sync=True)
-    _model_name = Unicode('BonoboModel').tag(sync=True)
-    _view_module = Unicode('bonobo-jupyter').tag(sync=True)
-    _model_module = Unicode('bonobo-jupyter').tag(sync=True)
+    _view_name = Unicode("BonoboView").tag(sync=True)
+    _model_name = Unicode("BonoboModel").tag(sync=True)
+    _view_module = Unicode("bonobo-jupyter").tag(sync=True)
+    _model_module = Unicode("bonobo-jupyter").tag(sync=True)
     value = List().tag(sync=True)

bonobo/contrib/opendatasoft/__init__.py

@@ -9,24 +9,24 @@ from bonobo.util.objects import ValueHolder
 
 
 def path_str(path):
-    return path if path.startswith('/') else '/' + path
+    return path if path.startswith("/") else "/" + path
 
 
 class OpenDataSoftAPI(Configurable):
     dataset = Option(str, positional=True)
-    endpoint = Option(str, required=False, default='{scheme}://{netloc}{path}')
-    scheme = Option(str, required=False, default='https')
-    netloc = Option(str, required=False, default='data.opendatasoft.com')
-    path = Option(path_str, required=False, default='/api/records/1.0/search/')
+    endpoint = Option(str, required=False, default="{scheme}://{netloc}{path}")
+    scheme = Option(str, required=False, default="https")
+    netloc = Option(str, required=False, default="data.opendatasoft.com")
+    path = Option(path_str, required=False, default="/api/records/1.0/search/")
     rows = Option(int, required=False, default=500)
     limit = Option(int, required=False)
-    timezone = Option(str, required=False, default='Europe/Paris')
+    timezone = Option(str, required=False, default="Europe/Paris")
     kwargs = Option(dict, required=False, default=dict)
 
     @ContextProcessor
     def compute_path(self, context):
-        params = (('dataset', self.dataset), ('timezone', self.timezone)) + tuple(sorted(self.kwargs.items()))
-        yield self.endpoint.format(scheme=self.scheme, netloc=self.netloc, path=self.path) + '?' + urlencode(params)
+        params = (("dataset", self.dataset), ("timezone", self.timezone)) + tuple(sorted(self.kwargs.items()))
+        yield self.endpoint.format(scheme=self.scheme, netloc=self.netloc, path=self.path) + "?" + urlencode(params)
 
     @ContextProcessor
     def start(self, context, base_url):
@@ -34,25 +34,19 @@ class OpenDataSoftAPI(Configurable):
 
     def __call__(self, base_url, start, *args, **kwargs):
         while (not self.limit) or (self.limit > start):
-            url = '{}&start={start}&rows={rows}'.format(
+            url = "{}&start={start}&rows={rows}".format(
                 base_url, start=start.value, rows=self.rows if not self.limit else min(self.rows, self.limit - start)
             )
             resp = requests.get(url)
-            records = resp.json().get('records', [])
+            records = resp.json().get("records", [])
 
             if not len(records):
                 break
 
             for row in records:
-                yield {
-                    **row.get('fields', {}),
-                    'geometry': row.get('geometry', {}),
-                    'recordid': row.get('recordid'),
-                }
+                yield {**row.get("fields", {}), "geometry": row.get("geometry", {}), "recordid": row.get("recordid")}
 
             start += self.rows
 
 
-__all__ = [
-    'OpenDataSoftAPI',
-]
+__all__ = ["OpenDataSoftAPI"]

bonobo/errors.py

@@ -16,10 +16,7 @@ class InactiveWritableError(InactiveIOError):
 class ValidationError(RuntimeError):
     def __init__(self, inst, message):
         super(ValidationError, self).__init__(
-            'Validation error in {class_name}: {message}'.format(
-                class_name=type(inst).__name__,
-                message=message,
-            )
+            "Validation error in {class_name}: {message}".format(class_name=type(inst).__name__, message=message)
         )
 
 
@@ -41,9 +38,8 @@ class AbstractError(UnrecoverableError, NotImplementedError):
 
     def __init__(self, method):
         super().__init__(
-            'Call to abstract method {class_name}.{method_name}(...): missing implementation.'.format(
-                class_name=get_name(method.__self__),
-                method_name=get_name(method),
+            "Call to abstract method {class_name}.{method_name}(...): missing implementation.".format(
+                class_name=get_name(method.__self__), method_name=get_name(method)
             )
         )
 

bonobo/examples/__init__.py

@@ -8,40 +8,21 @@ from bonobo.util.statistics import Timer
 def get_argument_parser(parser=None):
     parser = bonobo.get_argument_parser(parser=parser)
 
+    parser.add_argument("--limit", "-l", type=int, default=None, help="If set, limits the number of processed lines.")
     parser.add_argument(
-        '--limit',
-        '-l',
-        type=int,
-        default=None,
-        help='If set, limits the number of processed lines.'
-    )
-    parser.add_argument(
-        '--print',
-        '-p',
-        action='store_true',
-        default=False,
-        help='If set, pretty prints before writing to output file.'
+        "--print", "-p", action="store_true", default=False, help="If set, pretty prints before writing to output file."
     )
 
-    parser.add_argument(
-        '--strategy',
-        '-s',
-        type=str,
-        choices=STRATEGIES.keys(),
-        default=DEFAULT_STRATEGY,
-    )
+    parser.add_argument("--strategy", "-s", type=str, choices=STRATEGIES.keys(), default=DEFAULT_STRATEGY)
 
     return parser
 
 
 def get_graph_options(options):
-    _limit = options.pop('limit', None)
-    _print = options.pop('print', False)
+    _limit = options.pop("limit", None)
+    _print = options.pop("print", False)
 
-    return {
-        '_limit': (bonobo.Limit(_limit), ) if _limit else (),
-        '_print': (bonobo.PrettyPrinter(), ) if _print else (),
-    }
+    return {"_limit": (bonobo.Limit(_limit),) if _limit else (), "_print": (bonobo.PrettyPrinter(),) if _print else ()}
 
 
 def run(get_graph, get_services, *, parser=None):
@@ -49,38 +30,29 @@ def run(get_graph, get_services, *, parser=None):
 
     with bonobo.parse_args(parser) as options:
         with Timer() as timer:
-            print(
-                'Options:', ' '.join(
-                    '{}={}'.format(k, v)
-                    for k, v in sorted(options.items())
-                )
-            )
+            print("Options:", " ".join("{}={}".format(k, v) for k, v in sorted(options.items())))
             retval = bonobo.run(
-                get_graph(**get_graph_options(options)),
-                services=get_services(),
-                strategy=options['strategy'],
+                get_graph(**get_graph_options(options)), services=get_services(), strategy=options["strategy"]
             )
-        print('Execution time:', timer)
-        print('Return value:', retval)
-        print('XStatus:', retval.xstatus)
+        print("Execution time:", timer)
+        print("Return value:", retval)
+        print("XStatus:", retval.xstatus)
         return retval.xstatus
 
 
 def get_minor_version():
-    return '.'.join(bonobo.__version__.split('.')[:2])
+    return ".".join(bonobo.__version__.split(".")[:2])
 
 
 def get_datasets_dir(*dirs):
-    home_dir = os.path.expanduser('~')
-    target_dir = os.path.join(
-        home_dir, '.cache/bonobo', get_minor_version(), *dirs
-    )
+    home_dir = os.path.expanduser("~")
+    target_dir = os.path.join(home_dir, ".cache/bonobo", get_minor_version(), *dirs)
     os.makedirs(target_dir, exist_ok=True)
     return target_dir
 
 
 def get_services():
     return {
-        'fs': bonobo.open_fs(get_datasets_dir('datasets')),
-        'fs.static': bonobo.open_examples_fs('datasets', 'static'),
+        "fs": bonobo.open_fs(get_datasets_dir("datasets")),
+        "fs.static": bonobo.open_examples_fs("datasets", "static"),
     }

bonobo/examples/__main__.py

@@ -1,5 +1,5 @@
-if __name__ == '__main__':
+if __name__ == "__main__":
     from bonobo.commands import entrypoint
     import sys
 
-    entrypoint(['examples'] + sys.argv[1:])
+    entrypoint(["examples"] + sys.argv[1:])

bonobo/examples/clock.py

@@ -14,15 +14,12 @@ def extract():
 
 def get_graph():
     graph = bonobo.Graph()
-    graph.add_chain(
-        extract,
-        print,
-    )
+    graph.add_chain(extract, print)
 
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = bonobo.get_argument_parser()
     with bonobo.parse_args(parser):
         bonobo.run(get_graph())

bonobo/examples/datasets/__main__.py

@@ -6,24 +6,16 @@ from bonobo.examples import get_datasets_dir, get_minor_version, get_services
 from bonobo.examples.datasets.coffeeshops import get_graph as get_coffeeshops_graph
 from bonobo.examples.datasets.fablabs import get_graph as get_fablabs_graph
 
-graph_factories = {
-    'coffeeshops': get_coffeeshops_graph,
-    'fablabs': get_fablabs_graph,
-}
+graph_factories = {"coffeeshops": get_coffeeshops_graph, "fablabs": get_fablabs_graph}
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = examples.get_argument_parser()
-    parser.add_argument(
-        '--target', '-t', choices=graph_factories.keys(), nargs='+'
-    )
-    parser.add_argument('--sync', action='store_true', default=False)
+    parser.add_argument("--target", "-t", choices=graph_factories.keys(), nargs="+")
+    parser.add_argument("--sync", action="store_true", default=False)
 
     with bonobo.parse_args(parser) as options:
         graph_options = examples.get_graph_options(options)
-        graph_names = list(
-            options['target']
-            if options['target'] else sorted(graph_factories.keys())
-        )
+        graph_names = list(options["target"] if options["target"] else sorted(graph_factories.keys()))
 
         # Create a graph with all requested subgraphs
         graph = bonobo.Graph()
@@ -32,29 +24,20 @@ if __name__ == '__main__':
 
         bonobo.run(graph, services=get_services())
 
-        if options['sync']:
+        if options["sync"]:
             # TODO: when parallel option for node will be implemented, need to be rewriten to use a graph.
             import boto3
 
-            s3 = boto3.client('s3')
+            s3 = boto3.client("s3")
 
             local_dir = get_datasets_dir()
             for root, dirs, files in os.walk(local_dir):
                 for filename in files:
                     local_path = os.path.join(root, filename)
                     relative_path = os.path.relpath(local_path, local_dir)
-                    s3_path = os.path.join(
-                        get_minor_version(), relative_path
-                    )
+                    s3_path = os.path.join(get_minor_version(), relative_path)
 
                     try:
-                        s3.head_object(
-                            Bucket='bonobo-examples', Key=s3_path
-                        )
+                        s3.head_object(Bucket="bonobo-examples", Key=s3_path)
                     except Exception:
-                        s3.upload_file(
-                            local_path,
-                            'bonobo-examples',
-                            s3_path,
-                            ExtraArgs={'ACL': 'public-read'}
-                        )
+                        s3.upload_file(local_path, "bonobo-examples", s3_path, ExtraArgs={"ACL": "public-read"})

bonobo/examples/datasets/coffeeshops.py

@@ -1,63 +1,39 @@
-"""
-
-"""
 import sys
 
 import bonobo
 from bonobo import examples
 from bonobo.contrib.opendatasoft import OpenDataSoftAPI as ODSReader
 from bonobo.examples import get_services
+from bonobo.structs.graphs import PartialGraph
 
 
 def get_graph(graph=None, *, _limit=(), _print=()):
     graph = graph or bonobo.Graph()
 
-    producer = graph.add_chain(
-        ODSReader(
-            dataset='liste-des-cafes-a-un-euro',
-            netloc='opendata.paris.fr'
-        ),
-        *_limit,
-        bonobo.UnpackItems(0),
-        bonobo.Rename(
-            name='nom_du_cafe',
-            address='adresse',
-            zipcode='arrondissement'
-        ),
-        bonobo.Format(city='Paris', country='France'),
-        bonobo.OrderFields(
-            [
-                'name', 'address', 'zipcode', 'city', 'country',
-                'geometry', 'geoloc'
-            ]
-        ),
-        *_print,
+    producer = (
+        graph.get_cursor()
+        >> ODSReader(dataset="liste-des-cafes-a-un-euro", netloc="opendata.paris.fr")
+        >> PartialGraph(*_limit)
+        >> bonobo.UnpackItems(0)
+        >> bonobo.Rename(name="nom_du_cafe", address="adresse", zipcode="arrondissement")
+        >> bonobo.Format(city="Paris", country="France")
+        >> bonobo.OrderFields(["name", "address", "zipcode", "city", "country", "geometry", "geoloc"])
+        >> PartialGraph(*_print)
     )
 
     # Comma separated values.
-    graph.add_chain(
-        bonobo.CsvWriter(
-            'coffeeshops.csv',
-            fields=['name', 'address', 'zipcode', 'city'],
-            delimiter=','
-        ),
-        _input=producer.output,
+    graph.get_cursor(producer.output) >> bonobo.CsvWriter(
+        "coffeeshops.csv", fields=["name", "address", "zipcode", "city"], delimiter=","
     )
 
     # Standard JSON
-    graph.add_chain(
-        bonobo.JsonWriter(path='coffeeshops.json'),
-        _input=producer.output,
-    )
+    graph.get_cursor(producer.output) >> bonobo.JsonWriter(path="coffeeshops.json")
 
     # Line-delimited JSON
-    graph.add_chain(
-        bonobo.LdjsonWriter(path='coffeeshops.ldjson'),
-        _input=producer.output,
-    )
+    graph.get_cursor(producer.output) >> bonobo.LdjsonWriter(path="coffeeshops.ldjson")
 
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/datasets/fablabs.py

@@ -25,27 +25,21 @@ from bonobo.examples import get_services
 try:
     import pycountry
 except ImportError as exc:
-    raise ImportError(
-        'You must install package "pycountry" to run this example.'
-    ) from exc
+    raise ImportError('You must install package "pycountry" to run this example.') from exc
 
-API_DATASET = 'fablabs@public-us'
+API_DATASET = "fablabs@public-us"
 ROWS = 100
 
 
 def _getlink(x):
-    return x.get('url', None)
+    return x.get("url", None)
 
 
 def normalize(row):
     result = {
         **row,
-        'links':
-        list(filter(None, map(_getlink, json.loads(row.get('links'))))),
-        'country':
-        pycountry.countries.get(
-            alpha_2=row.get('country_code', '').upper()
-        ).name,
+        "links": list(filter(None, map(_getlink, json.loads(row.get("links"))))),
+        "country": pycountry.countries.get(alpha_2=row.get("country_code", "").upper()).name,
     }
     return result
 
@@ -58,10 +52,10 @@ def get_graph(graph=None, *, _limit=(), _print=()):
         normalize,
         bonobo.UnpackItems(0),
         *_print,
-        bonobo.JsonWriter(path='fablabs.json'),
+        bonobo.JsonWriter(path="fablabs.json"),
     )
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/empty.py

@@ -19,7 +19,7 @@ def get_graph():
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = bonobo.get_argument_parser()
     with bonobo.parse_args(parser):
         bonobo.run(get_graph())

bonobo/examples/environ.py

@@ -21,7 +21,7 @@ def get_graph():
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = bonobo.get_argument_parser()
     with bonobo.parse_args(parser):
         bonobo.run(get_graph())

bonobo/examples/files/csv_handlers.py

@@ -7,12 +7,12 @@ from bonobo.examples.files.services import get_services
 
 def get_graph(*, _limit=None, _print=False):
     return bonobo.Graph(
-        bonobo.CsvReader('coffeeshops.csv'),
-        *((bonobo.Limit(_limit), ) if _limit else ()),
-        *((bonobo.PrettyPrinter(), ) if _print else ()),
-        bonobo.CsvWriter('coffeeshops.csv', fs='fs.output')
+        bonobo.CsvReader("coffeeshops.csv"),
+        *((bonobo.Limit(_limit),) if _limit else ()),
+        *((bonobo.PrettyPrinter(),) if _print else ()),
+        bonobo.CsvWriter("coffeeshops.csv", fs="fs.output")
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/files/json_handlers.py

@@ -9,24 +9,17 @@ def get_graph(*, _limit=None, _print=False):
     graph = bonobo.Graph()
 
     trunk = graph.add_chain(
-        bonobo.JsonReader('theaters.json', fs='fs.static'),
-        *((bonobo.Limit(_limit), ) if _limit else ()),
+        bonobo.JsonReader("theaters.json", fs="fs.static"), *((bonobo.Limit(_limit),) if _limit else ())
     )
 
     if _print:
         graph.add_chain(bonobo.PrettyPrinter(), _input=trunk.output)
 
-    graph.add_chain(
-        bonobo.JsonWriter('theaters.output.json', fs='fs.output'),
-        _input=trunk.output
-    )
-    graph.add_chain(
-        bonobo.LdjsonWriter('theaters.output.ldjson', fs='fs.output'),
-        _input=trunk.output
-    )
+    graph.add_chain(bonobo.JsonWriter("theaters.output.json", fs="fs.output"), _input=trunk.output)
+    graph.add_chain(bonobo.LdjsonWriter("theaters.output.ldjson", fs="fs.output"), _input=trunk.output)
 
     return graph
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/files/pickle_handlers.py

@@ -1,4 +1,4 @@
-'''
+"""
 This example shows how a different file system service can be injected
 into a transformation (as compressing pickled objects often makes sense
 anyways).  The pickle itself contains a list of lists as follows:
@@ -25,7 +25,7 @@ https://www.kaggle.com/uciml/sms-spam-collection-dataset/downloads/sms-spam-coll
 The transformation (1) reads the pickled data, (2) marks and shortens
 messages categorized as spam, and (3) prints the output.
 
-'''
+"""
 
 import sys
 
@@ -36,14 +36,12 @@ from bonobo import examples
 
 
 def cleanse_sms(category, sms):
-    if category == 'spam':
-        sms_clean = '**MARKED AS SPAM** ' + sms[0:50] + (
-            '...' if len(sms) > 50 else ''
-        )
-    elif category == 'ham':
+    if category == "spam":
+        sms_clean = "**MARKED AS SPAM** " + sms[0:50] + ("..." if len(sms) > 50 else "")
+    elif category == "ham":
         sms_clean = sms
     else:
-        raise ValueError('Unknown category {!r}.'.format(category))
+        raise ValueError("Unknown category {!r}.".format(category))
 
     return category, sms, sms_clean
 
@@ -53,7 +51,7 @@ def get_graph(*, _limit=(), _print=()):
 
     graph.add_chain(
         # spam.pkl is within the gzipped tarball
-        bonobo.PickleReader('spam.pkl'),
+        bonobo.PickleReader("spam.pkl"),
         *_limit,
         cleanse_sms,
         *_print,
@@ -63,11 +61,8 @@ def get_graph(*, _limit=(), _print=()):
 
 
 def get_services():
-    return {
-        **examples.get_services(), 'fs':
-        TarFS(bonobo.get_examples_path('datasets', 'static', 'spam.tgz'))
-    }
+    return {**examples.get_services(), "fs": TarFS(bonobo.get_examples_path("datasets", "static", "spam.tgz"))}
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/files/services.py

@@ -2,7 +2,4 @@ from bonobo import examples, open_fs
 
 
 def get_services():
-    return {
-        **examples.get_services(),
-        'fs.output': open_fs(),
-    }
+    return {**examples.get_services(), "fs.output": open_fs()}

bonobo/examples/files/text_handlers.py

@@ -7,20 +7,20 @@ from bonobo.examples.files.services import get_services
 
 def skip_comments(line):
     line = line.strip()
-    if not line.startswith('#'):
+    if not line.startswith("#"):
         yield line
 
 
 def get_graph(*, _limit=(), _print=()):
     return bonobo.Graph(
-        bonobo.FileReader('passwd.txt', fs='fs.static'),
+        bonobo.FileReader("passwd.txt", fs="fs.static"),
         skip_comments,
         *_limit,
-        lambda s: s.split(':')[0],
+        lambda s: s.split(":")[0],
         *_print,
-        bonobo.FileWriter('usernames.txt', fs='fs.output'),
+        bonobo.FileWriter("usernames.txt", fs="fs.output"),
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(examples.run(get_graph, get_services))

bonobo/examples/types/__main__.py

@@ -1,7 +1,7 @@
 import bonobo
 from bonobo.examples.types.strings import get_graph
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = bonobo.get_argument_parser()
     with bonobo.parse_args(parser):
         bonobo.run(get_graph())

bonobo/examples/types/strings.py

@@ -18,13 +18,13 @@ import bonobo
 
 
 def extract():
-    yield 'foo'
-    yield 'bar'
-    yield 'baz'
+    yield "foo"
+    yield "bar"
+    yield "baz"
 
 
 def transform(s):
-    return '{} ({})'.format(s.title(), randint(10, 99))
+    return "{} ({})".format(s.title(), randint(10, 99))
 
 
 def load(s):
@@ -35,7 +35,7 @@ def get_graph():
     return bonobo.Graph(extract, transform, load)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     parser = bonobo.get_argument_parser()
     with bonobo.parse_args(parser):
         bonobo.run(get_graph())

bonobo/execution/contexts/__init__.py

@@ -9,8 +9,4 @@ from bonobo.execution.contexts.graph import GraphExecutionContext
 from bonobo.execution.contexts.node import NodeExecutionContext
 from bonobo.execution.contexts.plugin import PluginExecutionContext
 
-__all__ = [
-    'GraphExecutionContext',
-    'NodeExecutionContext',
-    'PluginExecutionContext',
-]
+__all__ = ["GraphExecutionContext", "NodeExecutionContext", "PluginExecutionContext"]

bonobo/execution/contexts/base.py

@@ -62,12 +62,12 @@ class Lifecycle:
 
         """
         if self._defunct:
-            return '!'
+            return "!"
         if not self.started:
-            return ' '
+            return " "
         if not self.stopped:
-            return '+'
-        return '-'
+            return "+"
+        return "-"
 
     def __enter__(self):
         self.start()
@@ -78,31 +78,31 @@ class Lifecycle:
 
     def get_flags_as_string(self):
         if self._defunct:
-            return term.red('[defunct]')
+            return term.red("[defunct]")
         if self.killed:
-            return term.lightred('[killed]')
+            return term.lightred("[killed]")
         if self.stopped:
-            return term.lightblack('[done]')
-        return ''
+            return term.lightblack("[done]")
+        return ""
 
     def start(self):
         if self.started:
-            raise RuntimeError('This context is already started ({}).'.format(get_name(self)))
+            raise RuntimeError("This context is already started ({}).".format(get_name(self)))
 
         self._started = True
 
     def stop(self):
         if not self.started:
-            raise RuntimeError('This context cannot be stopped as it never started ({}).'.format(get_name(self)))
+            raise RuntimeError("This context cannot be stopped as it never started ({}).".format(get_name(self)))
 
         self._stopped = True
 
     def kill(self):
         if not self.started:
-            raise RuntimeError('Cannot kill an unstarted context.')
+            raise RuntimeError("Cannot kill an unstarted context.")
 
         if self.stopped:
-            raise RuntimeError('Cannot kill a stopped context.')
+            raise RuntimeError("Cannot kill a stopped context.")
 
         self._killed = True
 
@@ -119,10 +119,10 @@ class Lifecycle:
 
     def as_dict(self):
         return {
-            'status': self.status,
-            'name': self.name,
-            'stats': self.get_statistics_as_string(),
-            'flags': self.get_flags_as_string(),
+            "status": self.status,
+            "name": self.name,
+            "stats": self.get_statistics_as_string(),
+            "flags": self.get_flags_as_string(),
         }
 
 

bonobo/execution/contexts/graph.py

@@ -63,7 +63,7 @@ class BaseGraphExecutionContext(BaseContext):
         self.services = create_container(services)
 
         # Probably not a good idea to use it unless you really know what you're doing. But you can access the context.
-        self.services['__graph_context'] = self
+        self.services["__graph_context"] = self
 
         for i, node_context in enumerate(self):
             outputs = self.graph.outputs_of(i)

bonobo/execution/contexts/node.py

@@ -19,7 +19,7 @@ from bonobo.util.statistics import WithStatistics
 
 logger = logging.getLogger(__name__)
 
-UnboundArguments = namedtuple('UnboundArguments', ['args', 'kwargs'])
+UnboundArguments = namedtuple("UnboundArguments", ["args", "kwargs"])
 
 
 class NodeExecutionContext(BaseContext, WithStatistics):
@@ -46,13 +46,13 @@ class NodeExecutionContext(BaseContext, WithStatistics):
         :param _outputs: output queues (optional)
         """
         BaseContext.__init__(self, wrapped, parent=parent)
-        WithStatistics.__init__(self, 'in', 'out', 'err', 'warn')
+        WithStatistics.__init__(self, "in", "out", "err", "warn")
 
         # Services: how we'll access external dependencies
         if services:
             if self.parent:
                 raise RuntimeError(
-                    'Having services defined both in GraphExecutionContext and child NodeExecutionContext is not supported, for now.'
+                    "Having services defined both in GraphExecutionContext and child NodeExecutionContext is not supported, for now."
                 )
             self.services = create_container(services)
         else:
@@ -70,11 +70,11 @@ class NodeExecutionContext(BaseContext, WithStatistics):
         self._stack = None
 
     def __str__(self):
-        return self.__name__ + self.get_statistics_as_string(prefix=' ')
+        return self.__name__ + self.get_statistics_as_string(prefix=" ")
 
     def __repr__(self):
         name, type_name = get_name(self), get_name(type(self))
-        return '<{}({}{}){}>'.format(type_name, self.status, name, self.get_statistics_as_string(prefix=' '))
+        return "<{}({}{}){}>".format(type_name, self.status, name, self.get_statistics_as_string(prefix=" "))
 
     def start(self):
         """
@@ -97,13 +97,13 @@ class NodeExecutionContext(BaseContext, WithStatistics):
                     # Not normal to have a partially configured object here, so let's warn the user instead of having get into
                     # the hard trouble of understanding that by himself.
                     raise TypeError(
-                        'Configurables should be instanciated before execution starts.\nGot {!r}.\n'.format(
+                        "Configurables should be instanciated before execution starts.\nGot {!r}.\n".format(
                             self.wrapped
                         )
                     ) from exc
                 else:
                     raise TypeError(
-                        'Configurables should be instanciated before execution starts.\nGot {!r}.\n'.format(
+                        "Configurables should be instanciated before execution starts.\nGot {!r}.\n".format(
                             self.wrapped
                         )
                     )
@@ -120,7 +120,7 @@ class NodeExecutionContext(BaseContext, WithStatistics):
         The actual infinite loop for this transformation.
 
         """
-        logger.debug('Node loop starts for {!r}.'.format(self))
+        logger.debug("Node loop starts for {!r}.".format(self))
 
         while self.should_loop:
             try:
@@ -128,7 +128,7 @@ class NodeExecutionContext(BaseContext, WithStatistics):
             except InactiveReadableError:
                 break
 
-        logger.debug('Node loop ends for {!r}.'.format(self))
+        logger.debug("Node loop ends for {!r}.".format(self))
 
     def step(self):
         try:
@@ -137,10 +137,7 @@ class NodeExecutionContext(BaseContext, WithStatistics):
             raise
         except Empty:
             sleep(TICK_PERIOD)  # XXX: How do we determine this constant?
-        except (
-                NotImplementedError,
-                UnrecoverableError,
-        ):
+        except (NotImplementedError, UnrecoverableError):
             self.fatal(sys.exc_info())  # exit loop
         except Exception:  # pylint: disable=broad-except
             self.error(sys.exc_info())  # does not exit loop
@@ -208,20 +205,20 @@ class NodeExecutionContext(BaseContext, WithStatistics):
 
     def set_input_type(self, input_type):
         if self._input_type is not None:
-            raise RuntimeError('Cannot override input type, already have %r.', self._input_type)
+            raise RuntimeError("Cannot override input type, already have %r.", self._input_type)
 
         if type(input_type) is not type:
-            raise UnrecoverableTypeError('Input types must be regular python types.')
+            raise UnrecoverableTypeError("Input types must be regular python types.")
 
         if not issubclass(input_type, tuple):
-            raise UnrecoverableTypeError('Input types must be subclasses of tuple (and act as tuples).')
+            raise UnrecoverableTypeError("Input types must be subclasses of tuple (and act as tuples).")
 
         self._input_type = input_type
 
     def get_input_fields(self):
-        return self._input_type._fields if self._input_type and hasattr(self._input_type, '_fields') else None
+        return self._input_type._fields if self._input_type and hasattr(self._input_type, "_fields") else None
 
-    def set_input_fields(self, fields, typename='Bag'):
+    def set_input_fields(self, fields, typename="Bag"):
         self.set_input_type(BagType(typename, fields))
 
     ### Output type and fields
@@ -231,20 +228,20 @@ class NodeExecutionContext(BaseContext, WithStatistics):
 
     def set_output_type(self, output_type):
         if self._output_type is not None:
-            raise RuntimeError('Cannot override output type, already have %r.', self._output_type)
+            raise RuntimeError("Cannot override output type, already have %r.", self._output_type)
 
         if type(output_type) is not type:
-            raise UnrecoverableTypeError('Output types must be regular python types.')
+            raise UnrecoverableTypeError("Output types must be regular python types.")
 
         if not issubclass(output_type, tuple):
-            raise UnrecoverableTypeError('Output types must be subclasses of tuple (and act as tuples).')
+            raise UnrecoverableTypeError("Output types must be subclasses of tuple (and act as tuples).")
 
         self._output_type = output_type
 
     def get_output_fields(self):
-        return self._output_type._fields if self._output_type and hasattr(self._output_type, '_fields') else None
+        return self._output_type._fields if self._output_type and hasattr(self._output_type, "_fields") else None
 
-    def set_output_fields(self, fields, typename='Bag'):
+    def set_output_fields(self, fields, typename="Bag"):
         self.set_output_type(BagType(typename, fields))
 
     ### Attributes
@@ -273,11 +270,11 @@ class NodeExecutionContext(BaseContext, WithStatistics):
             self.step()
 
     def error(self, exc_info, *, level=logging.ERROR):
-        self.increment('err')
+        self.increment("err")
         super().error(exc_info, level=level)
 
     def fatal(self, exc_info, *, level=logging.CRITICAL):
-        self.increment('err')
+        self.increment("err")
         super().fatal(exc_info, level=level)
         self.input.shutdown()
 
@@ -306,8 +303,9 @@ class NodeExecutionContext(BaseContext, WithStatistics):
                     input_bag = self._input_type(*input_bag)
             except Exception as exc:
                 raise UnrecoverableTypeError(
-                    'Input type changed to incompatible type between calls to {!r}.\nGot {!r} which is not of type {!r}.'.
-                    format(self.wrapped, input_bag, self._input_type)
+                    "Input type changed to incompatible type between calls to {!r}.\nGot {!r} which is not of type {!r}.".format(
+                        self.wrapped, input_bag, self._input_type
+                    )
                 ) from exc
 
         # Store or check input length, which is a soft fallback in case we're just using tuples
@@ -315,12 +313,12 @@ class NodeExecutionContext(BaseContext, WithStatistics):
             self._input_length = len(input_bag)
         elif len(input_bag) != self._input_length:
             raise UnrecoverableTypeError(
-                'Input length changed between calls to {!r}.\nExpected {} but got {}: {!r}.'.format(
+                "Input length changed between calls to {!r}.\nExpected {} but got {}: {!r}.".format(
                     self.wrapped, self._input_length, len(input_bag), input_bag
                 )
             )
 
-        self.increment('in')  # XXX should that go before type check ?
+        self.increment("in")  # XXX should that go before type check ?
 
         return input_bag
 
@@ -366,7 +364,7 @@ class NodeExecutionContext(BaseContext, WithStatistics):
         """
 
         if not _control:
-            self.increment('out')
+            self.increment("out")
 
         for output in self.outputs:
             output.put(value)
@@ -406,8 +404,9 @@ class AsyncNodeExecutionContext(NodeExecutionContext):
                     input_bag = self._input_type(*input_bag)
             except Exception as exc:
                 raise UnrecoverableTypeError(
-                    'Input type changed to incompatible type between calls to {!r}.\nGot {!r} which is not of type {!r}.'.
-                    format(self.wrapped, input_bag, self._input_type)
+                    "Input type changed to incompatible type between calls to {!r}.\nGot {!r} which is not of type {!r}.".format(
+                        self.wrapped, input_bag, self._input_type
+                    )
                 ) from exc
 
         # Store or check input length, which is a soft fallback in case we're just using tuples
@@ -415,12 +414,12 @@ class AsyncNodeExecutionContext(NodeExecutionContext):
             self._input_length = len(input_bag)
         elif len(input_bag) != self._input_length:
             raise UnrecoverableTypeError(
-                'Input length changed between calls to {!r}.\nExpected {} but got {}: {!r}.'.format(
+                "Input length changed between calls to {!r}.\nExpected {} but got {}: {!r}.".format(
                     self.wrapped, self._input_length, len(input_bag), input_bag
                 )
             )
 
-        self.increment('in')  # XXX should that go before type check ?
+        self.increment("in")  # XXX should that go before type check ?
 
         return input_bag
 
@@ -443,18 +442,18 @@ def split_token(output):
     flags, i, len_output, data_allowed = set(), 0, len(output), True
     while i < len_output and isflag(output[i]):
         if output[i].must_be_first and i:
-            raise ValueError('{} flag must be first.'.format(output[i]))
+            raise ValueError("{} flag must be first.".format(output[i]))
         if i and output[i - 1].must_be_last:
-            raise ValueError('{} flag must be last.'.format(output[i - 1]))
+            raise ValueError("{} flag must be last.".format(output[i - 1]))
         if output[i] in flags:
-            raise ValueError('Duplicate flag {}.'.format(output[i]))
+            raise ValueError("Duplicate flag {}.".format(output[i]))
         flags.add(output[i])
         data_allowed &= output[i].allows_data
         i += 1
 
     output = output[i:]
     if not data_allowed and len(output):
-        raise ValueError('Output data provided after a flag that does not allow data.')
+        raise ValueError("Output data provided after a flag that does not allow data.")
 
     return flags, output
 
@@ -465,7 +464,7 @@ def concat_types(t1, l1, t2, l2):
     if t1 == t2 == tuple:
         return tuple
 
-    f1 = t1._fields if hasattr(t1, '_fields') else tuple(range(l1))
-    f2 = t2._fields if hasattr(t2, '_fields') else tuple(range(l2))
+    f1 = t1._fields if hasattr(t1, "_fields") else tuple(range(l1))
+    f2 = t2._fields if hasattr(t2, "_fields") else tuple(range(l2))
 
-    return BagType('Inherited', f1 + f2)
+    return BagType("Inherited", f1 + f2)

bonobo/execution/events.py

@@ -27,12 +27,12 @@
 
 from whistle import Event
 
-START = 'execution.start'
-STARTED = 'execution.started'
-TICK = 'execution.tick'
-STOP = 'execution.stop'
-STOPPED = 'execution.stopped'
-KILL = 'execution.kill'
+START = "execution.start"
+STARTED = "execution.started"
+TICK = "execution.tick"
+STOP = "execution.stop"
+STOPPED = "execution.stopped"
+KILL = "execution.kill"
 
 
 class ExecutionEvent(Event):

bonobo/execution/strategies/__init__.py

@@ -6,22 +6,23 @@ In the future, the two strategies that would really benefit bonobo are subproces
 at home if you want to give it a shot.
 
 """
-from bonobo.execution.strategies.executor import ProcessPoolExecutorStrategy, ThreadPoolExecutorStrategy, \
-    AsyncThreadPoolExecutorStrategy
+from bonobo.execution.strategies.executor import (
+    ProcessPoolExecutorStrategy,
+    ThreadPoolExecutorStrategy,
+    AsyncThreadPoolExecutorStrategy,
+)
 from bonobo.execution.strategies.naive import NaiveStrategy
 
-__all__ = [
-    'create_strategy',
-]
+__all__ = ["create_strategy"]
 
 STRATEGIES = {
-    'naive': NaiveStrategy,
-    'processpool': ProcessPoolExecutorStrategy,
-    'threadpool': ThreadPoolExecutorStrategy,
-    'aio_threadpool': AsyncThreadPoolExecutorStrategy,
+    "naive": NaiveStrategy,
+    "processpool": ProcessPoolExecutorStrategy,
+    "threadpool": ThreadPoolExecutorStrategy,
+    "aio_threadpool": AsyncThreadPoolExecutorStrategy,
 }
 
-DEFAULT_STRATEGY = 'threadpool'
+DEFAULT_STRATEGY = "threadpool"
 
 
 def create_strategy(name=None):
@@ -40,13 +41,13 @@ def create_strategy(name=None):
     if name is None:
         name = DEFAULT_STRATEGY
 
-    logging.debug('Creating execution strategy {!r}...'.format(name))
+    logging.debug("Creating execution strategy {!r}...".format(name))
 
     try:
         factory = STRATEGIES[name]
     except KeyError as exc:
         raise RuntimeError(
-            'Invalid strategy {}. Available choices: {}.'.format(repr(name), ', '.join(sorted(STRATEGIES.keys())))
+            "Invalid strategy {}. Available choices: {}.".format(repr(name), ", ".join(sorted(STRATEGIES.keys())))
         ) from exc
 
     return factory()

bonobo/execution/strategies/base.py

@@ -6,6 +6,7 @@ class Strategy:
     Base class for execution strategies.
 
     """
+
     GraphExecutionContextType = GraphExecutionContext
 
     def __init__(self, GraphExecutionContextType=None):
@@ -13,7 +14,7 @@ class Strategy:
 
     def create_graph_execution_context(self, graph, *args, GraphExecutionContextType=None, **kwargs):
         if not len(graph):
-            raise ValueError('You provided an empty graph, which does not really make sense. Please add some nodes.')
+            raise ValueError("You provided an empty graph, which does not really make sense. Please add some nodes.")
         return (GraphExecutionContextType or self.GraphExecutionContextType)(graph, *args, **kwargs)
 
     def execute(self, graph, *args, **kwargs):

bonobo/execution/strategies/executor.py

@@ -36,14 +36,14 @@ class ExecutorStrategy(Strategy):
             try:
                 context.start(self.get_starter(executor, futures))
             except Exception:
-                logger.critical('Exception caught while starting execution context.', exc_info=sys.exc_info())
+                logger.critical("Exception caught while starting execution context.", exc_info=sys.exc_info())
 
             while context.alive:
                 try:
                     context.tick()
                 except KeyboardInterrupt:
                     logging.getLogger(__name__).warning(
-                        'KeyboardInterrupt received. Trying to terminate the nodes gracefully.'
+                        "KeyboardInterrupt received. Trying to terminate the nodes gracefully."
                     )
                     context.kill()
                     break
@@ -61,13 +61,13 @@ class ExecutorStrategy(Strategy):
                         node.loop()
                 except Exception:
                     logging.getLogger(__name__).critical(
-                        'Critical error in threadpool node starter.', exc_info=sys.exc_info()
+                        "Critical error in threadpool node starter.", exc_info=sys.exc_info()
                     )
 
             try:
                 futures.append(executor.submit(_runner))
             except Exception:
-                logging.getLogger(__name__).critical('futures.append', exc_info=sys.exc_info())
+                logging.getLogger(__name__).critical("futures.append", exc_info=sys.exc_info())
 
         return starter
 
@@ -85,7 +85,7 @@ class AsyncThreadPoolExecutorStrategy(ThreadPoolExecutorStrategy):
     def __init__(self, GraphExecutionContextType=None):
         if not settings.ALPHA.get():
             raise NotImplementedError(
-                '{} is experimental, you need to explicitely activate it using ALPHA=True in system env.'.format(
+                "{} is experimental, you need to explicitely activate it using ALPHA=True in system env.".format(
                     get_name(self)
                 )
             )

bonobo/nodes/__init__.py

@@ -5,4 +5,4 @@ from bonobo.nodes.io import *
 from bonobo.nodes.io import __all__ as _all_io
 from bonobo.nodes.throttle import RateLimited
 
-__all__ = _all_basics + _all_io + ['Filter', 'RateLimited']
+__all__ = _all_basics + _all_io + ["Filter", "RateLimited"]

bonobo/nodes/basics.py

@@ -13,18 +13,18 @@ from bonobo.util.term import CLEAR_EOL
 from mondrian import term
 
 __all__ = [
-    'FixedWindow',
-    'Format',
-    'Limit',
-    'OrderFields',
-    'PrettyPrinter',
-    'Rename',
-    'SetFields',
-    'Tee',
-    'UnpackItems',
-    'count',
-    'identity',
-    'noop',
+    "FixedWindow",
+    "Format",
+    "Limit",
+    "OrderFields",
+    "PrettyPrinter",
+    "Rename",
+    "SetFields",
+    "Tee",
+    "UnpackItems",
+    "count",
+    "identity",
+    "noop",
 ]
 
 
@@ -43,6 +43,7 @@ class Limit(Configurable):
     TODO: simplify into a closure building factory?
 
     """
+
     limit = Option(positional=True, default=10)
 
     @ContextProcessor
@@ -69,7 +70,7 @@ def Tee(f):
 
 def _shorten(s, w):
     if w and len(s) > w:
-        s = s[0:w - 3] + '...'
+        s = s[0 : w - 3] + "..."
     return s
 
 
@@ -78,28 +79,31 @@ class PrettyPrinter(Configurable):
         int,
         default=term.get_size()[0],
         required=False,
-        __doc__='''
+        __doc__="""
         If set, truncates the output values longer than this to this width.
-    '''
+    """,
     )
 
     filter = Method(
-        default=
-        (lambda self, index, key, value: (value is not None) and (not isinstance(key, str) or not key.startswith('_'))),
-        __doc__='''
+        default=(
+            lambda self, index, key, value: (value is not None)
+            and (not isinstance(key, str) or not key.startswith("_"))
+        ),
+        __doc__="""
             A filter that determine what to print.
             
             Default is to ignore any key starting with an underscore and none values.
-        '''
+        """,
     )
 
     @ContextProcessor
     def context(self, context):
-        context.setdefault('_jupyter_html', None)
+        context.setdefault("_jupyter_html", None)
         yield context
         if context._jupyter_html is not None:
             from IPython.display import display, HTML
-            display(HTML('\n'.join(['<table>'] + context._jupyter_html + ['</table>'])))
+
+            display(HTML("\n".join(["<table>"] + context._jupyter_html + ["</table>"])))
 
     def __call__(self, context, *args, **kwargs):
         if not settings.QUIET:
@@ -120,49 +124,44 @@ class PrettyPrinter(Configurable):
 
     def format_quiet(self, index, key, value, *, fields=None):
         # XXX should we implement argnames here ?
-        return ' '.join(((' ' if index else '-'), str(key), ':', str(value).strip()))
+        return " ".join(((" " if index else "-"), str(key), ":", str(value).strip()))
 
     def print_console(self, context, *args, **kwargs):
-        print('\u250c')
+        print("\u250c")
         for index, (key, value) in enumerate(itertools.chain(enumerate(args), kwargs.items())):
             if self.filter(index, key, value):
                 print(self.format_console(index, key, value, fields=context.get_input_fields()))
-        print('\u2514')
+        print("\u2514")
 
     def format_console(self, index, key, value, *, fields=None):
         fields = fields or []
         if not isinstance(key, str):
             if len(fields) > key and str(key) != str(fields[key]):
-                key = '{}{}'.format(fields[key], term.lightblack('[{}]'.format(key)))
+                key = "{}{}".format(fields[key], term.lightblack("[{}]".format(key)))
             else:
                 key = str(index)
 
-        prefix = '\u2502 {} = '.format(key)
+        prefix = "\u2502 {} = ".format(key)
         prefix_length = len(prefix)
 
         def indent(text, prefix):
             for i, line in enumerate(text.splitlines()):
-                yield (prefix if i else '') + line + CLEAR_EOL + '\n'
+                yield (prefix if i else "") + line + CLEAR_EOL + "\n"
 
-        repr_of_value = ''.join(
-            indent(pprint.pformat(value, width=self.max_width - prefix_length), '\u2502' + ' ' * (len(prefix) - 1))
+        repr_of_value = "".join(
+            indent(pprint.pformat(value, width=self.max_width - prefix_length), "\u2502" + " " * (len(prefix) - 1))
         ).strip()
-        return '{}{}{}'.format(prefix, repr_of_value.replace('\n', CLEAR_EOL + '\n'), CLEAR_EOL)
+        return "{}{}{}".format(prefix, repr_of_value.replace("\n", CLEAR_EOL + "\n"), CLEAR_EOL)
 
     def print_jupyter(self, context, *args):
         if not context._jupyter_html:
             context._jupyter_html = [
-                '<thead><tr>',
-                *map('<th>{}</th>'.format, map(html.escape, map(str,
-                                                                context.get_input_fields() or range(len(args))))),
-                '</tr></thead>',
+                "<thead><tr>",
+                *map("<th>{}</th>".format, map(html.escape, map(str, context.get_input_fields() or range(len(args))))),
+                "</tr></thead>",
             ]
 
-        context._jupyter_html += [
-            '<tr>',
-            *map('<td>{}</td>'.format, map(html.escape, map(repr, args))),
-            '</tr>',
-        ]
+        context._jupyter_html += ["<tr>", *map("<td>{}</td>".format, map(html.escape, map(repr, args))), "</tr>"]
 
 
 @use_no_input
@@ -211,7 +210,7 @@ def OrderFields(fields):
     @use_raw_input
     def _OrderFields(context, row):
         nonlocal fields
-        context.setdefault('remaining', None)
+        context.setdefault("remaining", None)
         if not context.output_type:
             context.remaining = list(sorted(set(context.get_input_fields()) - set(fields)))
             context.set_output_fields(fields + context.remaining)

bonobo/nodes/io/__init__.py

@@ -6,14 +6,14 @@ from .json import JsonReader, JsonWriter, LdjsonReader, LdjsonWriter
 from .pickle import PickleReader, PickleWriter
 
 __all__ = [
-    'CsvReader',
-    'CsvWriter',
-    'FileReader',
-    'FileWriter',
-    'JsonReader',
-    'JsonWriter',
-    'LdjsonReader',
-    'LdjsonWriter',
-    'PickleReader',
-    'PickleWriter',
+    "CsvReader",
+    "CsvWriter",
+    "FileReader",
+    "FileWriter",
+    "JsonReader",
+    "JsonWriter",
+    "LdjsonReader",
+    "LdjsonWriter",
+    "PickleReader",
+    "PickleWriter",
 ]

bonobo/nodes/io/base.py

@@ -13,22 +13,39 @@ class FileHandler(Configurable):
     """
 
     path = Option(
-        str, required=True, positional=True, __doc__='''
+        str,
+        required=True,
+        positional=True,
+        __doc__="""
         Path to use within the provided filesystem.
-    '''
+    """,
     )  # type: str
-    eol = Option(str, default='\n', __doc__='''
+    eol = Option(
+        str,
+        default="\n",
+        __doc__="""
         Character to use as line separator.
-    ''')  # type: str
-    mode = Option(str, __doc__='''
+    """,
+    )  # type: str
+    mode = Option(
+        str,
+        __doc__="""
         What mode to use for open() call.
-    ''')  # type: str
-    encoding = Option(str, default='utf-8', __doc__='''
+    """,
+    )  # type: str
+    encoding = Option(
+        str,
+        default="utf-8",
+        __doc__="""
         Encoding.
-    ''')  # type: str
-    fs = Service('fs', __doc__='''
+    """,
+    )  # type: str
+    fs = Service(
+        "fs",
+        __doc__="""
         The filesystem instance to use.
-    ''')  # type: str
+    """,
+    )  # type: str
 
     @ContextProcessor
     def file(self, context, *, fs):

bonobo/nodes/io/csv.py

@@ -35,18 +35,18 @@ class CsvHandler(FileHandler):
     quoting = Option(int, default=csv.excel.quoting, required=False)
 
     # Fields (renamed from headers)
-    headers = RenamedOption('fields')
+    headers = RenamedOption("fields")
     fields = Option(ensure_tuple, required=False)
 
     def get_dialect_kwargs(self):
         return {
-            'delimiter': self.delimiter,
-            'quotechar': self.quotechar,
-            'escapechar': self.escapechar,
-            'doublequote': self.doublequote,
-            'skipinitialspace': self.skipinitialspace,
-            'lineterminator': self.lineterminator,
-            'quoting': self.quoting,
+            "delimiter": self.delimiter,
+            "quotechar": self.quotechar,
+            "escapechar": self.escapechar,
+            "doublequote": self.doublequote,
+            "skipinitialspace": self.skipinitialspace,
+            "lineterminator": self.lineterminator,
+            "quoting": self.quoting,
         }
 
 
@@ -59,25 +59,25 @@ class CsvReader(FileReader, CsvHandler):
     skip = Option(
         int,
         default=0,
-        __doc__='''
+        __doc__="""
         If set and greater than zero, the reader will skip this amount of lines.
-    '''
+    """,
     )
 
     @Method(
         positional=False,
-        __doc__='''
+        __doc__="""
             Builds the CSV reader, a.k.a an object we can iterate, each iteration giving one line of fields, as an
             iterable.
             
             Defaults to builtin csv.reader(...), but can be overriden to fit your special needs.
-        '''
+        """,
     )
     def reader_factory(self, file):
         return csv.reader(file, **self.get_dialect_kwargs())
 
     def read(self, file, context, *, fs):
-        context.setdefault('skipped', 0)
+        context.setdefault("skipped", 0)
         reader = self.reader_factory(file)
         skip = self.skip
 
@@ -96,18 +96,18 @@ class CsvReader(FileReader, CsvHandler):
 @use_context
 class CsvWriter(FileWriter, CsvHandler):
     @Method(
-        __doc__='''
+        __doc__="""
             Builds the CSV writer, a.k.a an object we can pass a field collection to be written as one line in the
             target file.
             
             Defaults to builtin csv.writer(...).writerow, but can be overriden to fit your special needs.
-        '''
+        """
     )
     def writer_factory(self, file):
         return csv.writer(file, **self.get_dialect_kwargs()).writerow
 
     def write(self, file, context, *values, fs):
-        context.setdefault('lineno', 0)
+        context.setdefault("lineno", 0)
         fields = context.get_input_fields()
 
         if not context.lineno:
@@ -120,7 +120,7 @@ class CsvWriter(FileWriter, CsvHandler):
         if fields:
             if len(values) != len(fields):
                 raise ValueError(
-                    'Values length differs from input fields length. Expected: {}. Got: {}. Values: {!r}.'.format(
+                    "Values length differs from input fields length. Expected: {}. Got: {}. Values: {!r}.".format(
                         len(fields), len(values), values
                     )
                 )

bonobo/nodes/io/file.py

@@ -12,24 +12,28 @@ class FileReader(Reader, FileHandler):
     present. Extending it is usually the right way to create more specific file readers (like json, csv, etc.)
     """
 
-    mode = Option(str, default='r', __doc__='''
+    mode = Option(
+        str,
+        default="r",
+        __doc__="""
         What mode to use for open() call.
-    ''')  # type: str
+    """,
+    )  # type: str
 
     output_fields = Option(
         ensure_tuple,
         required=False,
-        __doc__='''
+        __doc__="""
         Specify the field names of output lines.
         Mutually exclusive with "output_type".
-    '''
+    """,
     )
     output_type = Option(
         required=False,
-        __doc__='''
+        __doc__="""
         Specify the type of output lines.
         Mutually exclusive with "output_fields".
-    '''
+    """,
     )
 
     @ContextProcessor
@@ -43,7 +47,7 @@ class FileReader(Reader, FileHandler):
         output_type = self.output_type
 
         if output_fields and output_type:
-            raise UnrecoverableError('Cannot specify both output_fields and output_type option.')
+            raise UnrecoverableError("Cannot specify both output_fields and output_type option.")
 
         if self.output_type:
             context.set_output_type(self.output_type)
@@ -72,16 +76,20 @@ class FileWriter(Writer, FileHandler):
     usually the right way to create more specific file writers (like json, csv, etc.)
     """
 
-    mode = Option(str, default='w+', __doc__='''
+    mode = Option(
+        str,
+        default="w+",
+        __doc__="""
         What mode to use for open() call.
-    ''')  # type: str
+    """,
+    )  # type: str
 
     def write(self, file, context, line, *, fs):
         """
         Write a row on the next line of opened file in context.
         """
-        context.setdefault('lineno', 0)
-        self._write_line(file, (self.eol if context.lineno else '') + line)
+        context.setdefault("lineno", 0)
+        self._write_line(file, (self.eol if context.lineno else "") + line)
         context.lineno += 1
         return NOT_MODIFIED
 

bonobo/nodes/io/json.py

@@ -9,13 +9,13 @@ from bonobo.nodes.io.file import FileReader, FileWriter
 
 
 class JsonHandler(FileHandler):
-    eol = ',\n'
-    prefix, suffix = '[', ']'
+    eol = ",\n"
+    prefix, suffix = "[", "]"
 
 
 class LdjsonHandler(FileHandler):
-    eol = '\n'
-    prefix, suffix = '', ''
+    eol = "\n"
+    prefix, suffix = "", ""
 
 
 class JsonReader(JsonHandler, FileReader):
@@ -58,16 +58,16 @@ class JsonWriter(JsonHandler, FileWriter):
         :param ctx:
         :param row:
         """
-        context.setdefault('lineno', 0)
+        context.setdefault("lineno", 0)
         fields = context.get_input_fields()
 
         if fields:
-            prefix = self.eol if context.lineno else ''
+            prefix = self.eol if context.lineno else ""
             self._write_line(file, prefix + json.dumps(OrderedDict(zip(fields, args))))
             context.lineno += 1
         else:
             for arg in args:
-                prefix = self.eol if context.lineno else ''
+                prefix = self.eol if context.lineno else ""
                 self._write_line(file, prefix + json.dumps(arg))
                 context.lineno += 1
 

bonobo/nodes/io/pickle.py

@@ -24,7 +24,7 @@ class PickleReader(FileReader, PickleHandler):
     Reads a Python pickle object and yields the items in dicts.
     """
 
-    mode = Option(str, default='rb')
+    mode = Option(str, default="rb")
 
     def read(self, file, context, *, fs):
         data = pickle.load(file)
@@ -47,7 +47,7 @@ class PickleReader(FileReader, PickleHandler):
 
         for row in iterator:
             if len(row) != fields_length:
-                raise ValueError('Received an object with {} items, expected {}.'.format(len(row), fields_length))
+                raise ValueError("Received an object with {} items, expected {}.".format(len(row), fields_length))
 
             yield tuple(row.values() if is_dict else row)
 
@@ -56,13 +56,13 @@ class PickleReader(FileReader, PickleHandler):
 
 @use_context
 class PickleWriter(FileWriter, PickleHandler):
-    mode = Option(str, default='wb')
+    mode = Option(str, default="wb")
 
     def write(self, file, context, item, *, fs):
         """
         Write a pickled item to the opened file.
         """
-        context.setdefault('lineno', 0)
+        context.setdefault("lineno", 0)
         file.write(pickle.dumps(item))
         context.lineno += 1
         return NOT_MODIFIED

bonobo/plugins/console.py

@@ -35,7 +35,7 @@ class ConsoleOutputPlugin(Plugin):
     isatty = False
 
     # Whether we're on windows, or a real operating system.
-    iswindows = (sys.platform == 'win32')
+    iswindows = sys.platform == "win32"
 
     def __init__(self):
         self.isatty = self._stdout.isatty()
@@ -55,9 +55,9 @@ class ConsoleOutputPlugin(Plugin):
         # Two options:
         # - move state to context
         # - forbid registering more than once
-        self.prefix = ''
+        self.prefix = ""
         self.counter = 0
-        self._append_cache = ''
+        self._append_cache = ""
 
         self.stdout = IOBuffer()
         self.redirect_stdout = redirect_stdout(self._stdout if self.iswindows else self.stdout)
@@ -78,13 +78,13 @@ class ConsoleOutputPlugin(Plugin):
         self.redirect_stderr.__exit__(None, None, None)
         self.redirect_stdout.__exit__(None, None, None)
 
-    def write(self, context, prefix='', rewind=True, append=None):
+    def write(self, context, prefix="", rewind=True, append=None):
         t_cnt = len(context)
 
         if not self.iswindows:
-            for line in self.stdout.switch().split('\n')[:-1]:
+            for line in self.stdout.switch().split("\n")[:-1]:
                 print(line + CLEAR_EOL, file=self._stdout)
-            for line in self.stderr.switch().split('\n')[:-1]:
+            for line in self.stderr.switch().split("\n")[:-1]:
                 print(line + CLEAR_EOL, file=self._stderr)
 
         alive_color = Style.BRIGHT
@@ -92,31 +92,36 @@ class ConsoleOutputPlugin(Plugin):
 
         for i in context.graph.topologically_sorted_indexes:
             node = context[i]
-            name_suffix = '({})'.format(i) if settings.DEBUG.get() else ''
+            name_suffix = "({})".format(i) if settings.DEBUG.get() else ""
 
             liveliness_color = alive_color if node.alive else dead_color
-            liveliness_prefix = ' {}{}{} '.format(liveliness_color, node.status, Style.RESET_ALL)
-            _line = ''.join((
-                liveliness_prefix,
-                node.name,
-                name_suffix,
-                ' ',
-                node.get_statistics_as_string(),
-                ' ',
-                node.get_flags_as_string(),
-                Style.RESET_ALL,
-                ' ',
-            ))
+            liveliness_prefix = " {}{}{} ".format(liveliness_color, node.status, Style.RESET_ALL)
+            _line = "".join(
+                (
+                    liveliness_prefix,
+                    node.name,
+                    name_suffix,
+                    " ",
+                    node.get_statistics_as_string(),
+                    " ",
+                    node.get_flags_as_string(),
+                    Style.RESET_ALL,
+                    " ",
+                )
+            )
             print(prefix + _line + CLEAR_EOL, file=self._stderr)
 
         if append:
             # todo handle multiline
             print(
-                ''.join((
-                    ' `-> ', ' '.join('{}{}{}: {}'.format(Style.BRIGHT, k, Style.RESET_ALL, v) for k, v in append),
-                    CLEAR_EOL
-                )),
-                file=self._stderr
+                "".join(
+                    (
+                        " `-> ",
+                        " ".join("{}{}{}: {}".format(Style.BRIGHT, k, Style.RESET_ALL, v) for k, v in append),
+                        CLEAR_EOL,
+                    )
+                ),
+                file=self._stderr,
             )
             t_cnt += 1
 
@@ -129,16 +134,17 @@ class ConsoleOutputPlugin(Plugin):
             if self.counter % 10 and self._append_cache:
                 append = self._append_cache
             else:
-                self._append_cache = append = (('Memory', '{0:.2f} Mb'.format(memory_usage())),
-                                               # ('Total time', '{0} s'.format(execution_time(harness))),
-                                               )
+                self._append_cache = append = (
+                    ("Memory", "{0:.2f} Mb".format(memory_usage())),
+                    # ('Total time', '{0} s'.format(execution_time(harness))),
+                )
         else:
             append = ()
         self.write(context, prefix=self.prefix, append=append, rewind=rewind)
         self.counter += 1
 
 
-class IOBuffer():
+class IOBuffer:
     """
     The role of IOBuffer is to overcome the problem of multiple threads wanting to write to stdout at the same time. It
     works a bit like a videogame: there are two buffers, one that is used to write, and one which is used to read from.
@@ -165,5 +171,6 @@ class IOBuffer():
 
 def memory_usage():
     import os, psutil
+
     process = psutil.Process(os.getpid())
-    return process.memory_info()[0] / float(2**20)
+    return process.memory_info()[0] / float(2 ** 20)

bonobo/plugins/jupyter.py

@@ -8,9 +8,9 @@ try:
     import IPython.core.display
 except ImportError as e:
     logging.exception(
-        'You must install Jupyter to use the bonobo Jupyter extension. Easiest way is to install the '
+        "You must install Jupyter to use the bonobo Jupyter extension. Easiest way is to install the "
         'optional "jupyter" dependencies with «pip install bonobo[jupyter]», but you can also install a '
-        'specific version by yourself.'
+        "specific version by yourself."
     )
 
 

bonobo/registry.py

@@ -5,23 +5,23 @@ from bonobo.nodes import (
     CsvReader, CsvWriter, FileReader, FileWriter, JsonReader, JsonWriter, PickleReader, PickleWriter
 )
 
-FILETYPE_CSV = 'text/csv'
-FILETYPE_JSON = 'application/json'
-FILETYPE_PICKLE = 'pickle'
-FILETYPE_PLAIN = 'text/plain'
+FILETYPE_CSV = "text/csv"
+FILETYPE_JSON = "application/json"
+FILETYPE_PICKLE = "pickle"
+FILETYPE_PLAIN = "text/plain"
 
-READER = 'reader'
-WRITER = 'writer'
+READER = "reader"
+WRITER = "writer"
 
 
 class Registry:
     ALIASES = {
-        'csv': FILETYPE_CSV,
-        'json': FILETYPE_JSON,
-        'pickle': FILETYPE_PICKLE,
-        'plain': FILETYPE_PLAIN,
-        'text': FILETYPE_PLAIN,
-        'txt': FILETYPE_PLAIN,
+        "csv": FILETYPE_CSV,
+        "json": FILETYPE_JSON,
+        "pickle": FILETYPE_PICKLE,
+        "plain": FILETYPE_PLAIN,
+        "text": FILETYPE_PLAIN,
+        "txt": FILETYPE_PLAIN,
     }
 
     FACTORIES = {
@@ -41,10 +41,10 @@ class Registry:
 
     def get_factory_for(self, kind, name, *, format=None):
         if not kind in self.FACTORIES:
-            raise KeyError('Unknown factory kind {!r}.'.format(kind))
+            raise KeyError("Unknown factory kind {!r}.".format(kind))
 
         if format is None and name is None:
-            raise RuntimeError('Cannot guess factory without at least a filename or a format.')
+            raise RuntimeError("Cannot guess factory without at least a filename or a format.")
 
         # Guess mimetype if possible
         if format is None:
@@ -62,7 +62,7 @@ class Registry:
 
         if format is None or not format in self.FACTORIES[kind]:
             raise RuntimeError(
-                'Could not resolve {kind} factory for {name} ({format}).'.format(kind=kind, name=name, format=format)
+                "Could not resolve {kind} factory for {name} ({format}).".format(kind=kind, name=name, format=format)
             )
 
         return self.FACTORIES[kind][format]

bonobo/settings.py

@@ -10,7 +10,7 @@ def to_bool(s):
     if type(s) is bool:
         return s
     if len(s):
-        if s.lower() in ('f', 'false', 'n', 'no', '0'):
+        if s.lower() in ("f", "false", "n", "no", "0"):
             return False
         return True
     return False
@@ -40,7 +40,7 @@ class Setting:
         self.formatter = formatter
 
     def __repr__(self):
-        return '<Setting {}={!r}>'.format(self.name, self.get())
+        return "<Setting {}={!r}>".format(self.name, self.get())
 
     def __eq__(self, other):
         return self.get() == other
@@ -51,7 +51,7 @@ class Setting:
     def set(self, value):
         value = self.formatter(value) if self.formatter else value
         if self.validator and not self.validator(value):
-            raise ValidationError(self, 'Invalid value {!r} for setting {!r}.'.format(value, self.name))
+            raise ValidationError(self, "Invalid value {!r} for setting {!r}.".format(value, self.name))
         self.value = value
 
     def set_if_true(self, value):
@@ -78,40 +78,37 @@ class Setting:
 
 
 # Debug/verbose mode.
-DEBUG = Setting('DEBUG', formatter=to_bool, default=False)
+DEBUG = Setting("DEBUG", formatter=to_bool, default=False)
 
 # Profile mode.
-PROFILE = Setting('PROFILE', formatter=to_bool, default=False)
+PROFILE = Setting("PROFILE", formatter=to_bool, default=False)
 
 # Alpha mode.
-ALPHA = Setting('ALPHA', formatter=to_bool, default=False)
+ALPHA = Setting("ALPHA", formatter=to_bool, default=False)
 
 # Quiet mode.
-QUIET = Setting('QUIET', formatter=to_bool, default=False)
+QUIET = Setting("QUIET", formatter=to_bool, default=False)
 
 # Logging level.
 LOGGING_LEVEL = Setting(
-    'LOGGING_LEVEL',
+    "LOGGING_LEVEL",
     formatter=logging._checkLevel,
     validator=logging._checkLevel,
-    default=lambda: logging.DEBUG if DEBUG.get() else logging.INFO
+    default=lambda: logging.DEBUG if DEBUG.get() else logging.INFO,
 )
 
 # Input/Output format for transformations
-IOFORMAT_ARG0 = 'arg0'
-IOFORMAT_KWARGS = 'kwargs'
+IOFORMAT_ARG0 = "arg0"
+IOFORMAT_KWARGS = "kwargs"
 
-IOFORMATS = {
-    IOFORMAT_ARG0,
-    IOFORMAT_KWARGS,
-}
+IOFORMATS = {IOFORMAT_ARG0, IOFORMAT_KWARGS}
 
-IOFORMAT = Setting('IOFORMAT', default=IOFORMAT_KWARGS, validator=IOFORMATS.__contains__)
+IOFORMAT = Setting("IOFORMAT", default=IOFORMAT_KWARGS, validator=IOFORMATS.__contains__)
 
 
 def check():
     if DEBUG.get() and QUIET.get():
-        raise RuntimeError('I cannot be verbose and quiet at the same time.')
+        raise RuntimeError("I cannot be verbose and quiet at the same time.")
 
 
 clear_all = Setting.clear_all

bonobo/structs/graphs.py

@@ -9,24 +9,51 @@ from graphviz.dot import Digraph
 from bonobo.constants import BEGIN
 from bonobo.util import get_name
 
-GraphRange = namedtuple('GraphRange', ['graph', 'input', 'output'])
+GraphRange = namedtuple("GraphRange", ["graph", "input", "output"])
+
 
 class GraphCursor:
-    def __init__(self, graph, node):
+    @property
+    def input(self):
+        return self.first
+
+    @property
+    def output(self):
+        return self.last
+
+    def __init__(self, graph, *, first=None, last=None):
         self.graph = graph
-        self.node = node
+        self.first = first or last
+        self.last = last
 
     def __rshift__(self, other):
         """ Self >> Other """
-        chain = self.graph.add_chain(other, _input=self.node)
-        return GraphCursor(chain.graph, chain.output)
+
+        if other == ...:
+            raise NotImplementedError(
+                "Expected something looking like a node, but got an Ellipsis (...). Did you forget to complete the graph?"
+            )
+
+        nodes = other.nodes if hasattr(other, "nodes") else [other]
+
+        if len(nodes):
+            chain = self.graph.add_chain(*nodes, _input=self.last)
+            return GraphCursor(chain.graph, first=self.first, last=chain.output)
+
+        return self
+
+
+class PartialGraph:
+    def __init__(self, *nodes):
+        self.nodes = list(nodes)
 
 
 class Graph:
     """
     Represents a directed graph of nodes.
     """
-    name = ''
+
+    name = ""
 
     def __init__(self, *chain):
         self.edges = {BEGIN: set()}
@@ -46,7 +73,7 @@ class Graph:
         return self.nodes[key]
 
     def get_cursor(self, ref=BEGIN):
-        return GraphCursor(self, self._resolve_index(ref))
+        return GraphCursor(self, last=self._resolve_index(ref))
 
     def outputs_of(self, idx, create=False):
         """ Get a set of the outputs for a given node index.
@@ -76,7 +103,7 @@ class Graph:
                 _last = self.add_node(node)
                 if not i and _name:
                     if _name in self.named:
-                        raise KeyError('Duplicate name {!r} in graph.'.format(_name))
+                        raise KeyError("Duplicate name {!r} in graph.".format(_name))
                     self.named[_name] = _last
                 if _first is None:
                     _first = _last
@@ -86,7 +113,7 @@ class Graph:
             if _output is not None:
                 self.outputs_of(_input, create=True).add(_output)
 
-            if hasattr(self, '_topologcally_sorted_indexes_cache'):
+            if hasattr(self, "_topologcally_sorted_indexes_cache"):
                 del self._topologcally_sorted_indexes_cache
 
             return GraphRange(self, _first, _last)
@@ -144,10 +171,10 @@ class Graph:
             return self._graphviz
         except AttributeError:
             g = Digraph()
-            g.attr(rankdir='LR')
-            g.node('BEGIN', shape='point')
+            g.attr(rankdir="LR")
+            g.node("BEGIN", shape="point")
             for i in self.outputs_of(BEGIN):
-                g.edge('BEGIN', str(i))
+                g.edge("BEGIN", str(i))
             for ix in self.topologically_sorted_indexes:
                 g.node(str(ix), label=get_name(self[ix]))
                 for iy in self.outputs_of(ix):
@@ -160,9 +187,9 @@ class Graph:
 
     def _repr_html_(self):
         try:
-            return '<div>{}</div><pre>{}</pre>'.format(self.graphviz._repr_svg_(), html.escape(repr(self)))
+            return "<div>{}</div><pre>{}</pre>".format(self.graphviz._repr_svg_(), html.escape(repr(self)))
         except (ExecutableNotFound, FileNotFoundError) as exc:
-            return '<strong>{}</strong>: {}'.format(type(exc).__name__, str(exc))
+            return "<strong>{}</strong>: {}".format(type(exc).__name__, str(exc))
 
     def _resolve_index(self, mixed):
         """
@@ -182,10 +209,10 @@ class Graph:
         if mixed in self.nodes:
             return self.nodes.index(mixed)
 
-        raise ValueError('Cannot find node matching {!r}.'.format(mixed))
+        raise ValueError("Cannot find node matching {!r}.".format(mixed))
 
 
 def _get_graphviz_node_id(graph, i):
     escaped_index = str(i)
     escaped_name = json.dumps(get_name(graph[i]))
-    return '{{{} [label={}]}}'.format(escaped_index, escaped_name)
+    return "{{{} [label={}]}}".format(escaped_index, escaped_name)

bonobo/structs/inputs.py

@@ -70,7 +70,7 @@ class Input(Queue, Readable, Writable):
 
         # Check we are actually able to receive data.
         if self._writable_runlevel < 1:
-            raise InactiveWritableError('Cannot put() on an inactive {}.'.format(Writable.__name__))
+            raise InactiveWritableError("Cannot put() on an inactive {}.".format(Writable.__name__))
 
         if data == END:
             self._writable_runlevel -= 1
@@ -85,7 +85,7 @@ class Input(Queue, Readable, Writable):
 
     def get(self, block=True, timeout=None):
         if not self.alive:
-            raise InactiveReadableError('Cannot get() on an inactive {}.'.format(Readable.__name__))
+            raise InactiveReadableError("Cannot get() on an inactive {}.".format(Readable.__name__))
 
         data = Queue.get(self, block, timeout)
 
@@ -94,7 +94,7 @@ class Input(Queue, Readable, Writable):
 
             if not self.alive:
                 raise InactiveReadableError(
-                    'Cannot get() on an inactive {} (runlevel just reached 0).'.format(Readable.__name__)
+                    "Cannot get() on an inactive {} (runlevel just reached 0).".format(Readable.__name__)
                 )
             return self.get(block, timeout)
 

bonobo/structs/tokens.py

@@ -3,7 +3,7 @@ class Token:
         self.__name__ = name
 
     def __repr__(self):
-        return '<{}>'.format(self.__name__)
+        return "<{}>".format(self.__name__)
 
 
 class Flag(Token):

bonobo/util/__init__.py

@@ -16,25 +16,25 @@ from bonobo.util.inspect import (
     istuple,
     istype,
 )
-from bonobo.util.objects import (get_name, get_attribute_or_create, ValueHolder)
+from bonobo.util.objects import get_name, get_attribute_or_create, ValueHolder
 
 # Bonobo's util API
 __all__ = [
-    'ValueHolder',
-    'cast',
-    'deprecated',
-    'deprecated_alias',
-    'ensure_tuple',
-    'get_attribute_or_create',
-    'get_name',
-    'inspect_node',
-    'isconfigurable',
-    'isconfigurabletype',
-    'iscontextprocessor',
-    'isdict',
-    'ismethod',
-    'isoption',
-    'istype',
-    'sortedlist',
-    'tuplize',
+    "ValueHolder",
+    "cast",
+    "deprecated",
+    "deprecated_alias",
+    "ensure_tuple",
+    "get_attribute_or_create",
+    "get_name",
+    "inspect_node",
+    "isconfigurable",
+    "isconfigurabletype",
+    "iscontextprocessor",
+    "isdict",
+    "ismethod",
+    "isoption",
+    "istype",
+    "sortedlist",
+    "tuplize",
 ]

bonobo/util/api.py

@@ -12,14 +12,14 @@ class ApiHelper:
         if graph:
             # This function must comply to the "graph" API interface, meaning it can bahave like bonobo.run.
             from inspect import signature
+
             parameters = list(signature(x).parameters)
-            required_parameters = {'plugins', 'services', 'strategy'}
-            assert len(parameters
-                       ) > 0 and parameters[0] == 'graph', 'First parameter of a graph api function must be "graph".'
-            assert required_parameters.intersection(
-                parameters
-            ) == required_parameters, 'Graph api functions must define the following parameters: ' + ', '.join(
-                sorted(required_parameters)
+            required_parameters = {"plugins", "services", "strategy"}
+            assert (
+                len(parameters) > 0 and parameters[0] == "graph"
+            ), 'First parameter of a graph api function must be "graph".'
+            assert required_parameters.intersection(parameters) == required_parameters, (
+                "Graph api functions must define the following parameters: " + ", ".join(sorted(required_parameters))
             )
 
         self.__all__.append(get_name(x))

bonobo/util/bags.py

@@ -71,16 +71,18 @@ class {typename}(tuple):
 {field_defs}
 '''
 
-_field_template = '''\
+_field_template = """\
     {name} = _property(_itemgetter({index:d}), doc={doc!r})
-'''.strip('\n')
-
-_reserved = frozenset(
-    ['_', '_cls', '_attrs', '_fields', 'get', '_asdict', '_replace', '_make', 'self', '_self', 'tuple'] + dir(tuple)
+""".strip(
+    "\n"
 )
 
-_multiple_underscores_pattern = re.compile('__+')
-_slugify_allowed_chars_pattern = re.compile(r'[^a-z0-9_]+', flags=re.IGNORECASE)
+_reserved = frozenset(
+    ["_", "_cls", "_attrs", "_fields", "get", "_asdict", "_replace", "_make", "self", "_self", "tuple"] + dir(tuple)
+)
+
+_multiple_underscores_pattern = re.compile("__+")
+_slugify_allowed_chars_pattern = re.compile(r"[^a-z0-9_]+", flags=re.IGNORECASE)
 
 
 def _uniquify(f):
@@ -90,13 +92,13 @@ def _uniquify(f):
     def _uniquified(x):
         nonlocal f, seen
         x = str(x)
-        v = v0 = _multiple_underscores_pattern.sub('_', f(x))
+        v = v0 = _multiple_underscores_pattern.sub("_", f(x))
         i = 0
         # if last character is not "allowed", let's start appending indexes right from the first iteration
         if len(x) and _slugify_allowed_chars_pattern.match(x[-1]):
-            v = '{}{}'.format(v0, i)
+            v = "{}{}".format(v0, i)
         while v in seen:
-            v = '{}{}'.format(v0, i)
+            v = "{}{}".format(v0, i)
             i += 1
         seen.add(v)
         return v
@@ -106,13 +108,13 @@ def _uniquify(f):
 
 def _make_valid_attr_name(x):
     if iskeyword(x):
-        x = '_' + x
+        x = "_" + x
     if x.isidentifier():
         return x
-    x = slugify(x, separator='_', regex_pattern=_slugify_allowed_chars_pattern)
+    x = slugify(x, separator="_", regex_pattern=_slugify_allowed_chars_pattern)
     if x.isidentifier():
         return x
-    x = '_' + x
+    x = "_" + x
     if x.isidentifier():
         return x
     raise ValueError(x)
@@ -124,23 +126,23 @@ def BagType(typename, fields, *, verbose=False, module=None):
 
     attrs = tuple(map(_uniquify(_make_valid_attr_name), fields))
     if type(fields) is str:
-        raise TypeError('BagType does not support providing fields as a string.')
+        raise TypeError("BagType does not support providing fields as a string.")
     fields = list(map(str, fields))
     typename = str(typename)
 
     for i, name in enumerate([typename] + fields):
         if type(name) is not str:
-            raise TypeError('Type names and field names must be strings, got {name!r}'.format(name=name))
+            raise TypeError("Type names and field names must be strings, got {name!r}".format(name=name))
         if not i:
             if not name.isidentifier():
-                raise ValueError('Type names must be valid identifiers: {name!r}'.format(name=name))
+                raise ValueError("Type names must be valid identifiers: {name!r}".format(name=name))
             if iskeyword(name):
-                raise ValueError('Type names cannot be a keyword: {name!r}'.format(name=name))
+                raise ValueError("Type names cannot be a keyword: {name!r}".format(name=name))
 
     seen = set()
     for name in fields:
         if name in seen:
-            raise ValueError('Encountered duplicate field name: {name!r}'.format(name=name))
+            raise ValueError("Encountered duplicate field name: {name!r}".format(name=name))
         seen.add(name)
 
     # Fill-in the class template
@@ -150,21 +152,24 @@ def BagType(typename, fields, *, verbose=False, module=None):
         attrs=attrs,
         num_fields=len(fields),
         arg_list=repr(attrs).replace("'", "")[1:-1],
-        repr_fmt=', '.join(('%r' if isinstance(fields[index], int) else '{name}=%r').format(name=name)
-                           for index, name in enumerate(attrs)),
-        field_defs='\n'.join(
+        repr_fmt=", ".join(
+            ("%r" if isinstance(fields[index], int) else "{name}=%r").format(name=name)
+            for index, name in enumerate(attrs)
+        ),
+        field_defs="\n".join(
             _field_template.format(
                 index=index,
                 name=name,
-                doc='Alias for ' +
-                ('field #{}'.format(index) if isinstance(fields[index], int) else repr(fields[index]))
-            ) for index, name in enumerate(attrs)
-        )
+                doc="Alias for "
+                + ("field #{}".format(index) if isinstance(fields[index], int) else repr(fields[index])),
+            )
+            for index, name in enumerate(attrs)
+        ),
     )
 
     # Execute the template string in a temporary namespace and support
     # tracing utilities by setting a value for frame.f_globals['__name__']
-    namespace = dict(__name__='namedtuple_%s' % typename)
+    namespace = dict(__name__="namedtuple_%s" % typename)
     exec(class_definition, namespace)
     result = namespace[typename]
     result._source = class_definition
@@ -178,7 +183,7 @@ def BagType(typename, fields, *, verbose=False, module=None):
     # specified a particular module.
     if module is None:
         try:
-            module = sys._getframe(1).f_globals.get('__name__', '__main__')
+            module = sys._getframe(1).f_globals.get("__name__", "__main__")
         except (AttributeError, ValueError):
             pass
     if module is not None:

bonobo/util/collections.py

@@ -25,7 +25,7 @@ def _with_length_check(f):
         if length is not None:
             if length != len(result):
                 raise TypeError(
-                    'Length check failed, expected {} fields but got {}: {!r}.'.format(length, len(result), result)
+                    "Length check failed, expected {} fields but got {}: {!r}.".format(length, len(result), result)
                 )
         return result
 
@@ -54,7 +54,7 @@ def ensure_tuple(tuple_or_mixed, *, cls=None):
     if isinstance(tuple_or_mixed, tuple):
         return tuple.__new__(cls, tuple_or_mixed)
 
-    return tuple.__new__(cls, (tuple_or_mixed, ))
+    return tuple.__new__(cls, (tuple_or_mixed,))
 
 
 def cast(type_):

bonobo/util/compat.py

@@ -5,13 +5,13 @@ import warnings
 def deprecated_alias(alias, func):
     @functools.wraps(func)
     def new_func(*args, **kwargs):
-        warnings.simplefilter('always', DeprecationWarning)  # turn off filter
+        warnings.simplefilter("always", DeprecationWarning)  # turn off filter
         warnings.warn(
             "Call to deprecated function alias {}, use {} instead.".format(alias, func.__name__),
             category=DeprecationWarning,
-            stacklevel=2
+            stacklevel=2,
         )
-        warnings.simplefilter('default', DeprecationWarning)  # reset filter
+        warnings.simplefilter("default", DeprecationWarning)  # reset filter
         return func(*args, **kwargs)
 
     return new_func
@@ -24,11 +24,11 @@ def deprecated(func):
 
     @functools.wraps(func)
     def new_func(*args, **kwargs):
-        warnings.simplefilter('always', DeprecationWarning)  # turn off filter
+        warnings.simplefilter("always", DeprecationWarning)  # turn off filter
         warnings.warn(
             "Call to deprecated function {}.".format(func.__name__), category=DeprecationWarning, stacklevel=2
         )
-        warnings.simplefilter('default', DeprecationWarning)  # reset filter
+        warnings.simplefilter("default", DeprecationWarning)  # reset filter
         return func(*args, **kwargs)
 
     return new_func

bonobo/util/envelopes.py

@@ -1,8 +1,8 @@
 from bonobo.structs.tokens import Flag
 
-F_INHERIT = Flag('Inherit')
+F_INHERIT = Flag("Inherit")
 
-F_NOT_MODIFIED = Flag('NotModified')
+F_NOT_MODIFIED = Flag("NotModified")
 F_NOT_MODIFIED.must_be_first = True
 F_NOT_MODIFIED.must_be_last = True
 F_NOT_MODIFIED.allows_data = False

bonobo/util/environ.py

@@ -5,12 +5,12 @@ import re
 import warnings
 from contextlib import contextmanager
 
-__escape_decoder = codecs.getdecoder('unicode_escape')
-__posix_variable = re.compile('\$\{[^\}]*\}')
+__escape_decoder = codecs.getdecoder("unicode_escape")
+__posix_variable = re.compile("\$\{[^\}]*\}")
 
 
 def parse_var(var):
-    name, value = var.split('=', 1)
+    name, value = var.split("=", 1)
 
     def decode_escaped(escaped):
         return __escape_decoder(escaped)[0]
@@ -29,15 +29,15 @@ def load_env_from_file(filename):
     Read an env file into a collection of (name, value) tuples.
     """
     if not os.path.exists(filename):
-        raise FileNotFoundError('Environment file {} does not exist.'.format(filename))
+        raise FileNotFoundError("Environment file {} does not exist.".format(filename))
 
     with open(filename) as f:
         for lineno, line in enumerate(f):
             line = line.strip()
-            if not line or line.startswith('#'):
+            if not line or line.startswith("#"):
                 continue
-            if '=' not in line:
-                raise SyntaxError('Invalid environment file syntax in {} at line {}.'.format(filename, lineno + 1))
+            if "=" not in line:
+                raise SyntaxError("Invalid environment file syntax in {} at line {}.".format(filename, lineno + 1))
 
             name, value = parse_var(line)
 
@@ -64,10 +64,10 @@ def get_argument_parser(parser=None):
     global _parser
     _parser = parser
 
-    _parser.add_argument('--default-env-file', '-E', action='append')
-    _parser.add_argument('--default-env', action='append')
-    _parser.add_argument('--env-file', action='append')
-    _parser.add_argument('--env', '-e', action='append')
+    _parser.add_argument("--default-env-file", "-E", action="append")
+    _parser.add_argument("--default-env", action="append")
+    _parser.add_argument("--env-file", action="append")
+    _parser.add_argument("--env", "-e", action="append")
 
     return _parser
 
@@ -89,10 +89,11 @@ def parse_args(mixed=None):
         global _parser
         if _parser is not None:
             warnings.warn(
-                'You are calling bonobo.parse_args() without a parser argument, but it looks like you created a parser before. You probably want to pass your parser to this call, or if creating a new parser here is really what you want to do, please create a new one explicitely to silence this warning.'
+                "You are calling bonobo.parse_args() without a parser argument, but it looks like you created a parser before. You probably want to pass your parser to this call, or if creating a new parser here is really what you want to do, please create a new one explicitely to silence this warning."
             )
         # use the api from bonobo namespace, in case a command patched it.
         import bonobo
+
         mixed = bonobo.get_argument_parser()
 
     if isinstance(mixed, argparse.ArgumentParser):
@@ -117,14 +118,14 @@ def parse_args(mixed=None):
     #   env-file sets something.)
     try:
         # Set default environment
-        for name, value in map(parse_var, options.pop('default_env', []) or []):
+        for name, value in map(parse_var, options.pop("default_env", []) or []):
             if not name in os.environ:
                 if not name in _backup:
                     _backup[name] = os.environ.get(name, None)
                 os.environ[name] = value
 
         # Read and set default environment from file(s)
-        for filename in options.pop('default_env_file', []) or []:
+        for filename in options.pop("default_env_file", []) or []:
             for name, value in load_env_from_file(filename):
                 if not name in os.environ:
                     if not name in _backup:
@@ -132,14 +133,14 @@ def parse_args(mixed=None):
                     os.environ[name] = value
 
         # Read and set environment from file(s)
-        for filename in options.pop('env_file', []) or []:
+        for filename in options.pop("env_file", []) or []:
             for name, value in load_env_from_file(filename):
                 if not name in _backup:
                     _backup[name] = os.environ.get(name, None)
                 os.environ[name] = value
 
         # Set environment
-        for name, value in map(parse_var, options.pop('env', []) or []):
+        for name, value in map(parse_var, options.pop("env", []) or []):
             if not name in _backup:
                 _backup[name] = os.environ.get(name, None)
             os.environ[name] = value

bonobo/util/errors.py

@@ -15,36 +15,32 @@ def sweeten_errors():
     except Exception as exc:
         SPACES = 2
         w = term.white
-        prefix = w('║' + ' ' * (SPACES - 1))
-        suffix = w(' ' * (SPACES - 1) + '║')
+        prefix = w("║" + " " * (SPACES - 1))
+        suffix = w(" " * (SPACES - 1) + "║")
 
-        pre_re = re.compile('([^`]*)`([^`]*)`([^`]*)')
+        pre_re = re.compile("([^`]*)`([^`]*)`([^`]*)")
 
         def format_arg(arg):
-            length = len(pre_re.sub('\\1\\2\\3', arg))
+            length = len(pre_re.sub("\\1\\2\\3", arg))
 
-            arg = pre_re.sub(w('\\1') + term.bold('\\2') + w('\\3'), arg)
-            arg = re.sub('^  \$ (.*)', term.lightblack('  $ ') + term.reset('\\1'), arg)
+            arg = pre_re.sub(w("\\1") + term.bold("\\2") + w("\\3"), arg)
+            arg = re.sub("^  \$ (.*)", term.lightblack("  $ ") + term.reset("\\1"), arg)
 
             return (arg, length)
 
         def f(*args):
-            return ''.join(args)
+            return "".join(args)
 
         term_width, term_height = term.get_size()
         line_length = min(80, term_width)
         for arg in exc.args:
             line_length = max(min(line_length, len(arg) + 2 * SPACES), 120)
 
-        print(f(w('╔' + '═' * (line_length - 2) + '╗')))
+        print(f(w("╔" + "═" * (line_length - 2) + "╗")))
         for i, arg in enumerate(exc.args):
 
             if i == 1:
-                print(f(
-                    prefix,
-                    ' ' * (line_length - 2 * SPACES),
-                    suffix,
-                ))
+                print(f(prefix, " " * (line_length - 2 * SPACES), suffix))
 
             arg_formatted, arg_length = format_arg(arg)
             if not i:
@@ -52,17 +48,17 @@ def sweeten_errors():
                 print(
                     f(
                         prefix,
-                        term.red_bg(term.bold(' ' + type(exc).__name__ + ' ')),
-                        ' ',
+                        term.red_bg(term.bold(" " + type(exc).__name__ + " ")),
+                        " ",
                         w(arg_formatted),
-                        ' ' * (line_length - (arg_length + 3 + len(type(exc).__name__) + 2 * SPACES)),
+                        " " * (line_length - (arg_length + 3 + len(type(exc).__name__) + 2 * SPACES)),
                         suffix,
                     )
                 )
             else:
                 # other lines
-                print(f(prefix, arg_formatted + ' ' * (line_length - arg_length - 2 * SPACES), suffix))
+                print(f(prefix, arg_formatted + " " * (line_length - arg_length - 2 * SPACES), suffix))
 
-        print(f(w('╚' + '═' * (line_length - 2) + '╝')))
+        print(f(w("╚" + "═" * (line_length - 2) + "╝")))
 
-        logging.getLogger().debug('This error was caused by the following exception chain.', exc_info=exc_info())
+        logging.getLogger().debug("This error was caused by the following exception chain.", exc_info=exc_info())

bonobo/util/inspect.py

@@ -9,6 +9,7 @@ def isconfigurable(mixed):
     :return: bool
     """
     from bonobo.config.configurables import Configurable
+
     return isinstance(mixed, Configurable)
 
 
@@ -32,7 +33,7 @@ def isconfigurabletype(mixed, *, strict=False):
     if isinstance(mixed, PartiallyConfigured):
         return True
 
-    if hasattr(mixed, '_partial') and mixed._partial:
+    if hasattr(mixed, "_partial") and mixed._partial:
         return True
 
     return False
@@ -47,6 +48,7 @@ def isoption(mixed):
     """
 
     from bonobo.config.options import Option
+
     return isinstance(mixed, Option)
 
 
@@ -58,6 +60,7 @@ def ismethod(mixed):
     :return: bool
     """
     from bonobo.config.options import Method
+
     return isinstance(mixed, Method)
 
 
@@ -69,6 +72,7 @@ def iscontextprocessor(x):
     :return: bool
     """
     from bonobo.config.processors import ContextProcessor
+
     return isinstance(x, ContextProcessor)
 
 
@@ -102,15 +106,7 @@ def istuple(mixed):
     return isinstance(mixed, tuple)
 
 
-ConfigurableInspection = namedtuple(
-    'ConfigurableInspection', [
-        'type',
-        'instance',
-        'options',
-        'processors',
-        'partial',
-    ]
-)
+ConfigurableInspection = namedtuple("ConfigurableInspection", ["type", "instance", "options", "processors", "partial"])
 
 ConfigurableInspection.__enter__ = lambda self: self
 ConfigurableInspection.__exit__ = lambda *exc_details: None
@@ -134,17 +130,11 @@ def inspect_node(mixed, *, _partial=None):
         inst, typ = None, mixed
     elif isconfigurable(mixed):
         inst, typ = mixed, type(mixed)
-    elif hasattr(mixed, 'func'):
+    elif hasattr(mixed, "func"):
         return inspect_node(mixed.func, _partial=(mixed.args, mixed.keywords))
     else:
         raise TypeError(
-            'Not a Configurable, nor a Configurable instance and not even a partially configured Configurable. Check your inputs.'
+            "Not a Configurable, nor a Configurable instance and not even a partially configured Configurable. Check your inputs."
         )
 
-    return ConfigurableInspection(
-        typ,
-        inst,
-        list(typ.__options__),
-        list(typ.__processors__),
-        _partial,
-    )
+    return ConfigurableInspection(typ, inst, list(typ.__options__), list(typ.__processors__), _partial)

bonobo/util/objects.py

@@ -11,7 +11,7 @@ class Wrapper:
 
     @property
     def __name__(self):
-        return getattr(self.wrapped, '__name__', getattr(type(self.wrapped), '__name__', repr(self.wrapped)))
+        return getattr(self.wrapped, "__name__", getattr(type(self.wrapped), "__name__", repr(self.wrapped)))
 
     name = __name__
 
@@ -142,10 +142,10 @@ class ValueHolder:
         return divmod(other, self._value)
 
     def __pow__(self, other):
-        return self._value**other
+        return self._value ** other
 
     def __rpow__(self, other):
-        return other**self._value
+        return other ** self._value
 
     def __ipow__(self, other):
         self._value **= other

bonobo/util/pkgs.py

@@ -4,5 +4,5 @@ from packaging.utils import canonicalize_name
 bonobo_packages = {}
 for p in pkg_resources.working_set:
     name = canonicalize_name(p.project_name)
-    if name.startswith('bonobo'):
+    if name.startswith("bonobo"):
         bonobo_packages[name] = p

bonobo/util/resolvers.py

@@ -23,8 +23,8 @@ class _ModulesRegistry(dict):
 
     def require(self, name):
         if name not in self:
-            bits = name.split('.')
-            filename = os.path.join(self.pathname, *bits[:-1], bits[-1] + '.py')
+            bits = name.split(".")
+            filename = os.path.join(self.pathname, *bits[:-1], bits[-1] + ".py")
             self[name] = _RequiredModule(runpy.run_path(filename, run_name=name))
         return self[name]
 
@@ -37,7 +37,7 @@ def _parse_option(option):
     :return: tuple
     """
     try:
-        key, val = option.split('=', 1)
+        key, val = option.split("=", 1)
     except ValueError:
         return option, True
 
@@ -75,7 +75,7 @@ def _resolve_transformations(transformations):
     transformations = transformations or []
     for t in transformations:
         try:
-            mod, attr = t.split(':', 1)
+            mod, attr = t.split(":", 1)
             yield getattr(registry.require(mod), attr)
         except ValueError:
             yield getattr(bonobo, t)

bonobo/util/statistics.py

@@ -10,8 +10,8 @@ class WithStatistics:
         return ((name, self.statistics[name]) for name in self.statistics_names)
 
     def get_statistics_as_string(self, *args, **kwargs):
-        stats = tuple('{0}={1}'.format(name, cnt) for name, cnt in self.get_statistics(*args, **kwargs) if cnt > 0)
-        return (kwargs.get('prefix', '') + ' '.join(stats)) if len(stats) else ''
+        stats = tuple("{0}={1}".format(name, cnt) for name, cnt in self.get_statistics(*args, **kwargs) if cnt > 0)
+        return (kwargs.get("prefix", "") + " ".join(stats)) if len(stats) else ""
 
     def increment(self, name, *, amount=1):
         self.statistics[name] += amount
@@ -35,4 +35,4 @@ class Timer:
         return self.__finish - self.__start
 
     def __str__(self):
-        return str(int(self.duration * 1000) / 1000.0) + 's'
+        return str(int(self.duration * 1000) / 1000.0) + "s"

bonobo/util/term.py

@@ -1,2 +1,2 @@
-CLEAR_EOL = '\033[0K'
-MOVE_CURSOR_UP = lambda n: '\033[{}A'.format(n)
+CLEAR_EOL = "\033[0K"
+MOVE_CURSOR_UP = lambda n: "\033[{}A".format(n)

bonobo/util/testing.py

@@ -26,20 +26,20 @@ def optional_contextmanager(cm, *, ignore=False):
 
 
 class FilesystemTester:
-    def __init__(self, extension='txt', mode='w', *, input_data=''):
+    def __init__(self, extension="txt", mode="w", *, input_data=""):
         self.extension = extension
         self.input_data = input_data
         self.mode = mode
 
     def get_services_for_reader(self, tmpdir):
-        fs, filename = open_fs(tmpdir), 'input.' + self.extension
+        fs, filename = open_fs(tmpdir), "input." + self.extension
         with fs.open(filename, self.mode) as fp:
             fp.write(self.input_data)
-        return fs, filename, {'fs': fs}
+        return fs, filename, {"fs": fs}
 
     def get_services_for_writer(self, tmpdir):
-        fs, filename = open_fs(tmpdir), 'output.' + self.extension
-        return fs, filename, {'fs': fs}
+        fs, filename = open_fs(tmpdir), "output." + self.extension
+        return fs, filename, {"fs": fs}
 
 
 class QueueList(list):
@@ -60,7 +60,7 @@ class BufferingContext:
         return self.buffer
 
     def get_buffer_args_as_dicts(self):
-        return [row._asdict() if hasattr(row, '_asdict') else dict(row) for row in self.buffer]
+        return [row._asdict() if hasattr(row, "_asdict") else dict(row) for row in self.buffer]
 
 
 class BufferingNodeExecutionContext(BufferingContext, NodeExecutionContext):
@@ -106,43 +106,37 @@ def runner_entrypoint(args):
 @runner
 def runner_module(args):
     """ Run bonobo using the bonobo.__main__ file, which is equivalent as doing "python -m bonobo ..."."""
-    with patch.object(sys, 'argv', ['bonobo', *args]):
-        return runpy.run_path(__main__.__file__, run_name='__main__')
+    with patch.object(sys, "argv", ["bonobo", *args]):
+        return runpy.run_path(__main__.__file__, run_name="__main__")
 
 
-all_runners = pytest.mark.parametrize('runner', [runner_entrypoint, runner_module])
+all_runners = pytest.mark.parametrize("runner", [runner_entrypoint, runner_module])
 all_environ_targets = pytest.mark.parametrize(
-    'target', [
-        (get_examples_path('environ.py'), ),
-        (
-            '-m',
-            'bonobo.examples.environ',
-        ),
-    ]
+    "target", [(get_examples_path("environ.py"),), ("-m", "bonobo.examples.environ")]
 )
 
 
 @all_runners
 @all_environ_targets
-class EnvironmentTestCase():
+class EnvironmentTestCase:
     def run_quiet(self, runner, *args):
-        return runner('run', '--quiet', *args)
+        return runner("run", "--quiet", *args)
 
     def run_environ(self, runner, *args, environ=None):
-        _environ = {'PATH': '/usr/bin'}
+        _environ = {"PATH": "/usr/bin"}
         if environ:
             _environ.update(environ)
 
-        with patch.dict('os.environ', _environ, clear=True):
+        with patch.dict("os.environ", _environ, clear=True):
             out, err = self.run_quiet(runner, *args)
-            assert 'SECRET' not in os.environ
-            assert 'PASSWORD' not in os.environ
-            if 'PATH' in _environ:
-                assert 'PATH' in os.environ
-                assert os.environ['PATH'] == _environ['PATH']
+            assert "SECRET" not in os.environ
+            assert "PASSWORD" not in os.environ
+            if "PATH" in _environ:
+                assert "PATH" in os.environ
+                assert os.environ["PATH"] == _environ["PATH"]
 
-        assert err == ''
-        return dict(map(lambda line: line.split(' ', 1), filter(None, out.split('\n'))))
+        assert err == ""
+        return dict(map(lambda line: line.split(" ", 1), filter(None, out.split("\n"))))
 
 
 class StaticNodeTest:
@@ -202,8 +196,8 @@ class ReaderTest(ConfigurableNodeTest):
 
     ReaderNodeType = None
 
-    extension = 'txt'
-    input_data = ''
+    extension = "txt"
+    input_data = ""
 
     @property
     def NodeType(self):
@@ -216,12 +210,12 @@ class ReaderTest(ConfigurableNodeTest):
         self.tmpdir = tmpdir
 
     def get_create_args(self, *args):
-        return (self.filename, ) + args
+        return (self.filename,) + args
 
     def test_customizable_output_type_transform_not_a_type(self):
         context = self.NodeExecutionContextType(
             self.create(*self.get_create_args(), output_type=str.upper, **self.get_create_kwargs()),
-            services=self.services
+            services=self.services,
         )
         with pytest.raises(TypeError):
             context.start()
@@ -229,9 +223,9 @@ class ReaderTest(ConfigurableNodeTest):
     def test_customizable_output_type_transform_not_a_tuple(self):
         context = self.NodeExecutionContextType(
             self.create(
-                *self.get_create_args(), output_type=type('UpperString', (str, ), {}), **self.get_create_kwargs()
+                *self.get_create_args(), output_type=type("UpperString", (str,), {}), **self.get_create_kwargs()
             ),
-            services=self.services
+            services=self.services,
         )
         with pytest.raises(TypeError):
             context.start()
@@ -242,8 +236,8 @@ class WriterTest(ConfigurableNodeTest):
 
     WriterNodeType = None
 
-    extension = 'txt'
-    input_data = ''
+    extension = "txt"
+    input_data = ""
 
     @property
     def NodeType(self):
@@ -256,7 +250,7 @@ class WriterTest(ConfigurableNodeTest):
         self.tmpdir = tmpdir
 
     def get_create_args(self, *args):
-        return (self.filename, ) + args
+        return (self.filename,) + args
 
     def readlines(self):
         with self.fs.open(self.filename) as fp:

tests/commands/test_clibasics.py

@@ -6,20 +6,14 @@ from bonobo.util.testing import all_runners
 def test_entrypoint():
     commands = {}
 
-    for command in pkg_resources.iter_entry_points('bonobo.commands'):
+    for command in pkg_resources.iter_entry_points("bonobo.commands"):
         commands[command.name] = command
 
-    assert not {
-        'convert',
-        'init',
-        'inspect',
-        'run',
-        'version',
-    }.difference(set(commands))
+    assert not {"convert", "init", "inspect", "run", "version"}.difference(set(commands))
 
 
 @all_runners
 def test_no_command(runner):
     _, err, exc = runner(catch_errors=True)
     assert type(exc) == SystemExit
-    assert 'error: the following arguments are required: command' in err
+    assert "error: the following arguments are required: command" in err

tests/commands/test_convert.py

@@ -8,10 +8,10 @@ from bonobo.util.testing import all_runners
 
 @all_runners
 def test_convert(runner, tmpdir):
-    csv_content = 'id;name\n1;Romain'
-    tmpdir.join('in.csv').write(csv_content)
+    csv_content = "id;name\n1;Romain"
+    tmpdir.join("in.csv").write(csv_content)
 
     with change_working_directory(tmpdir):
-        runner('convert', 'in.csv', 'out.csv')
+        runner("convert", "in.csv", "out.csv")
 
-    assert tmpdir.join('out.csv').read().strip() == csv_content
+    assert tmpdir.join("out.csv").read().strip() == csv_content

tests/commands/test_download.py

@@ -9,7 +9,7 @@ from bonobo.util.testing import all_runners
 
 @all_runners
 def test_download_works_for_examples(runner):
-    expected_bytes = b'hello world'
+    expected_bytes = b"hello world"
 
     class MockResponse(object):
         def __init__(self):
@@ -27,12 +27,13 @@ def test_download_works_for_examples(runner):
     fout = io.BytesIO()
     fout.close = lambda: None
 
-    with patch('bonobo.commands.download._open_url') as mock_open_url, \
-            patch('bonobo.commands.download.open') as mock_open:
+    with patch("bonobo.commands.download._open_url") as mock_open_url, patch(
+        "bonobo.commands.download.open"
+    ) as mock_open:
         mock_open_url.return_value = MockResponse()
         mock_open.return_value = fout
-        runner('download', 'examples/datasets/coffeeshops.txt')
-    expected_url = EXAMPLES_BASE_URL + 'datasets/coffeeshops.txt'
+        runner("download", "examples/datasets/coffeeshops.txt")
+    expected_url = EXAMPLES_BASE_URL + "datasets/coffeeshops.txt"
     mock_open_url.assert_called_once_with(expected_url)
 
     assert fout.getvalue() == expected_bytes
@@ -41,4 +42,4 @@ def test_download_works_for_examples(runner):
 @all_runners
 def test_download_fails_non_example(runner):
     with pytest.raises(ValueError):
-        runner('download', 'something/entirely/different.txt')
+        runner("download", "something/entirely/different.txt")

tests/commands/test_init.py

@@ -8,22 +8,22 @@ from bonobo.util.testing import all_runners
 
 @all_runners
 def test_init_file(runner, tmpdir):
-    target = tmpdir.join('foo.py')
+    target = tmpdir.join("foo.py")
     target_filename = str(target)
-    runner('init', target_filename)
+    runner("init", target_filename)
     assert os.path.exists(target_filename)
 
-    out, err = runner('run', target_filename)
-    assert out.replace('\n', ' ').strip() == 'Hello World'
+    out, err = runner("run", target_filename)
+    assert out.replace("\n", " ").strip() == "Hello World"
     assert not err
 
 
 @all_runners
-@pytest.mark.parametrize('template', InitCommand.TEMPLATES)
+@pytest.mark.parametrize("template", InitCommand.TEMPLATES)
 def test_init_file_templates(runner, template, tmpdir):
-    target = tmpdir.join('foo.py')
+    target = tmpdir.join("foo.py")
     target_filename = str(target)
-    runner('init', target_filename)
+    runner("init", target_filename)
     assert os.path.exists(target_filename)
-    out, err = runner('run', target_filename)
+    out, err = runner("run", target_filename)
     assert not err

tests/commands/test_run.py

@@ -7,42 +7,42 @@ from bonobo.util.testing import all_runners
 
 @all_runners
 def test_run(runner):
-    out, err = runner('run', '--quiet', get_examples_path('types/strings.py'))
-    out = out.split('\n')
-    assert out[0].startswith('Foo ')
-    assert out[1].startswith('Bar ')
-    assert out[2].startswith('Baz ')
+    out, err = runner("run", "--quiet", get_examples_path("types/strings.py"))
+    out = out.split("\n")
+    assert out[0].startswith("Foo ")
+    assert out[1].startswith("Bar ")
+    assert out[2].startswith("Baz ")
 
 
 @all_runners
 def test_run_module(runner):
-    out, err = runner('run', '--quiet', '-m', 'bonobo.examples.types.strings')
-    out = out.split('\n')
-    assert out[0].startswith('Foo ')
-    assert out[1].startswith('Bar ')
-    assert out[2].startswith('Baz ')
+    out, err = runner("run", "--quiet", "-m", "bonobo.examples.types.strings")
+    out = out.split("\n")
+    assert out[0].startswith("Foo ")
+    assert out[1].startswith("Bar ")
+    assert out[2].startswith("Baz ")
 
 
 @all_runners
 def test_run_path(runner):
-    out, err = runner('run', '--quiet', get_examples_path('types'))
-    out = out.split('\n')
-    assert out[0].startswith('Foo ')
-    assert out[1].startswith('Bar ')
-    assert out[2].startswith('Baz ')
+    out, err = runner("run", "--quiet", get_examples_path("types"))
+    out = out.split("\n")
+    assert out[0].startswith("Foo ")
+    assert out[1].startswith("Bar ")
+    assert out[2].startswith("Baz ")
 
 
 @all_runners
 def test_install_requirements_for_dir(runner):
-    dirname = get_examples_path('types')
-    with patch('bonobo.commands.run._install_requirements') as install_mock:
-        runner('run', '--install', dirname)
-    install_mock.assert_called_once_with(os.path.join(dirname, 'requirements.txt'))
+    dirname = get_examples_path("types")
+    with patch("bonobo.commands.run._install_requirements") as install_mock:
+        runner("run", "--install", dirname)
+    install_mock.assert_called_once_with(os.path.join(dirname, "requirements.txt"))
 
 
 @all_runners
 def test_install_requirements_for_file(runner):
-    dirname = get_examples_path('types')
-    with patch('bonobo.commands.run._install_requirements') as install_mock:
-        runner('run', '--install', os.path.join(dirname, 'strings.py'))
-    install_mock.assert_called_once_with(os.path.join(dirname, 'requirements.txt'))
+    dirname = get_examples_path("types")
+    with patch("bonobo.commands.run._install_requirements") as install_mock:
+        runner("run", "--install", os.path.join(dirname, "strings.py"))
+    install_mock.assert_called_once_with(os.path.join(dirname, "requirements.txt"))

tests/commands/test_run_environ.py

@@ -5,103 +5,104 @@ from bonobo.util.testing import EnvironmentTestCase
 
 @pytest.fixture
 def env1(tmpdir):
-    env_file = tmpdir.join('.env_one')
-    env_file.write('\n'.join((
-        'SECRET=unknown',
-        'PASSWORD=sweet',
-        'PATH=first',
-    )))
+    env_file = tmpdir.join(".env_one")
+    env_file.write("\n".join(("SECRET=unknown", "PASSWORD=sweet", "PATH=first")))
     return str(env_file)
 
 
 @pytest.fixture
 def env2(tmpdir):
-    env_file = tmpdir.join('.env_two')
-    env_file.write('\n'.join((
-        'PASSWORD=bitter',
-        "PATH='second'",
-    )))
+    env_file = tmpdir.join(".env_two")
+    env_file.write("\n".join(("PASSWORD=bitter", "PATH='second'")))
     return str(env_file)
 
 
 class TestDefaultEnvFile(EnvironmentTestCase):
     def test_run_with_default_env_file(self, runner, target, env1):
-        env = self.run_environ(runner, *target, '--default-env-file', env1)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'sweet'
-        assert env.get('PATH') == '/usr/bin'
+        env = self.run_environ(runner, *target, "--default-env-file", env1)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "sweet"
+        assert env.get("PATH") == "/usr/bin"
 
     def test_run_with_multiple_default_env_files(self, runner, target, env1, env2):
-        env = self.run_environ(runner, *target, '--default-env-file', env1, '--default-env-file', env2)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'sweet'
-        assert env.get('PATH') == '/usr/bin'
+        env = self.run_environ(runner, *target, "--default-env-file", env1, "--default-env-file", env2)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "sweet"
+        assert env.get("PATH") == "/usr/bin"
 
-        env = self.run_environ(runner, *target, '--default-env-file', env2, '--default-env-file', env1)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'bitter'
-        assert env.get('PATH') == '/usr/bin'
+        env = self.run_environ(runner, *target, "--default-env-file", env2, "--default-env-file", env1)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "bitter"
+        assert env.get("PATH") == "/usr/bin"
 
 
 class TestEnvFile(EnvironmentTestCase):
     def test_run_with_file(self, runner, target, env1):
-        env = self.run_environ(runner, *target, '--env-file', env1)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'sweet'
-        assert env.get('PATH') == 'first'
+        env = self.run_environ(runner, *target, "--env-file", env1)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "sweet"
+        assert env.get("PATH") == "first"
 
     def test_run_with_multiple_files(self, runner, target, env1, env2):
-        env = self.run_environ(runner, *target, '--env-file', env1, '--env-file', env2)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'bitter'
-        assert env.get('PATH') == 'second'
+        env = self.run_environ(runner, *target, "--env-file", env1, "--env-file", env2)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "bitter"
+        assert env.get("PATH") == "second"
 
-        env = self.run_environ(runner, *target, '--env-file', env2, '--env-file', env1)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'sweet'
-        assert env.get('PATH') == 'first'
+        env = self.run_environ(runner, *target, "--env-file", env2, "--env-file", env1)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "sweet"
+        assert env.get("PATH") == "first"
 
 
 class TestEnvFileCombinations(EnvironmentTestCase):
     def test_run_with_both_env_files(self, runner, target, env1, env2):
-        env = self.run_environ(runner, *target, '--default-env-file', env1, '--env-file', env2)
-        assert env.get('SECRET') == 'unknown'
-        assert env.get('PASSWORD') == 'bitter'
-        assert env.get('PATH') == 'second'
+        env = self.run_environ(runner, *target, "--default-env-file", env1, "--env-file", env2)
+        assert env.get("SECRET") == "unknown"
+        assert env.get("PASSWORD") == "bitter"
+        assert env.get("PATH") == "second"
 
     def test_run_with_both_env_files_then_overrides(self, runner, target, env1, env2):
         env = self.run_environ(
-            runner, *target, '--default-env-file', env1, '--env-file', env2, '--env', 'PASSWORD=mine', '--env',
-            'SECRET=s3cr3t'
+            runner,
+            *target,
+            "--default-env-file",
+            env1,
+            "--env-file",
+            env2,
+            "--env",
+            "PASSWORD=mine",
+            "--env",
+            "SECRET=s3cr3t"
         )
-        assert env.get('SECRET') == 's3cr3t'
-        assert env.get('PASSWORD') == 'mine'
-        assert env.get('PATH') == 'second'
+        assert env.get("SECRET") == "s3cr3t"
+        assert env.get("PASSWORD") == "mine"
+        assert env.get("PATH") == "second"
 
 
 class TestEnvVars(EnvironmentTestCase):
     def test_run_no_env(self, runner, target):
-        env = self.run_environ(runner, *target, environ={'USER': 'romain'})
-        assert env.get('USER') == 'romain'
+        env = self.run_environ(runner, *target, environ={"USER": "romain"})
+        assert env.get("USER") == "romain"
 
     def test_run_env(self, runner, target):
-        env = self.run_environ(runner, *target, '--env', 'USER=serious', environ={'USER': 'romain'})
-        assert env.get('USER') == 'serious'
+        env = self.run_environ(runner, *target, "--env", "USER=serious", environ={"USER": "romain"})
+        assert env.get("USER") == "serious"
 
     def test_run_env_mixed(self, runner, target):
-        env = self.run_environ(runner, *target, '--env', 'ONE=1', '--env', 'TWO="2"', environ={'USER': 'romain'})
-        assert env.get('USER') == 'romain'
-        assert env.get('ONE') == '1'
-        assert env.get('TWO') == '2'
+        env = self.run_environ(runner, *target, "--env", "ONE=1", "--env", 'TWO="2"', environ={"USER": "romain"})
+        assert env.get("USER") == "romain"
+        assert env.get("ONE") == "1"
+        assert env.get("TWO") == "2"
 
     def test_run_default_env(self, runner, target):
-        env = self.run_environ(runner, *target, '--default-env', 'USER=clown')
-        assert env.get('USER') == 'clown'
+        env = self.run_environ(runner, *target, "--default-env", "USER=clown")
+        assert env.get("USER") == "clown"
 
-        env = self.run_environ(runner, *target, '--default-env', 'USER=clown', environ={'USER': 'romain'})
-        assert env.get('USER') == 'romain'
+        env = self.run_environ(runner, *target, "--default-env", "USER=clown", environ={"USER": "romain"})
+        assert env.get("USER") == "romain"
 
         env = self.run_environ(
-            runner, *target, '--env', 'USER=serious', '--default-env', 'USER=clown', environ={'USER': 'romain'}
+            runner, *target, "--env", "USER=serious", "--default-env", "USER=clown", environ={"USER": "romain"}
         )
-        assert env.get('USER') == 'serious'
+        assert env.get("USER") == "serious"

tests/commands/test_version.py

@@ -4,17 +4,17 @@ from bonobo.util.testing import all_runners
 
 @all_runners
 def test_version(runner):
-    out, err = runner('version')
+    out, err = runner("version")
     out = out.strip()
-    assert out.startswith('bonobo ')
+    assert out.startswith("bonobo ")
     assert __version__ in out
 
-    out, err = runner('version', '-q')
+    out, err = runner("version", "-q")
     out = out.strip()
-    assert out.startswith('bonobo ')
+    assert out.startswith("bonobo ")
     assert __version__ in out
 
-    out, err = runner('version', '-qq')
+    out, err = runner("version", "-qq")
     out = out.strip()
-    assert not out.startswith('bonobo ')
-    assert __version__ in out
+    assert not out.startswith("bonobo ")
+    assert __version__ in out

tests/config/test_configurables.py

@@ -11,7 +11,7 @@ class NoOptConfigurable(Configurable):
 
 class MyConfigurable(Configurable):
     required_str = Option(str)
-    default_str = Option(str, default='foo')
+    default_str = Option(str, default="foo")
     integer = Option(int, required=False)
 
 
@@ -20,7 +20,7 @@ class MyHarderConfigurable(MyConfigurable):
 
 
 class MyBetterConfigurable(MyConfigurable):
-    required_str = Option(str, required=False, default='kaboom')
+    required_str = Option(str, required=False, default="kaboom")
 
 
 class MyConfigurableUsingPositionalOptions(MyConfigurable):
@@ -35,7 +35,7 @@ def test_missing_required_option_error():
 
     with pytest.raises(TypeError) as exc:
         MyConfigurable(_final=True)
-    assert exc.match('missing 1 required option:')
+    assert exc.match("missing 1 required option:")
 
 
 def test_missing_required_options_error():
@@ -44,29 +44,29 @@ def test_missing_required_options_error():
 
     with pytest.raises(TypeError) as exc:
         MyHarderConfigurable(_final=True)
-    assert exc.match('missing 2 required options:')
+    assert exc.match("missing 2 required options:")
 
 
 def test_extraneous_option_error():
     with pytest.raises(TypeError) as exc:
-        MyConfigurable(required_str='foo', hello='world')
-    assert exc.match('got 1 unexpected option:')
+        MyConfigurable(required_str="foo", hello="world")
+    assert exc.match("got 1 unexpected option:")
 
 
 def test_extraneous_options_error():
     with pytest.raises(TypeError) as exc:
-        MyConfigurable(required_str='foo', hello='world', acme='corp')
-    assert exc.match('got 2 unexpected options:')
+        MyConfigurable(required_str="foo", hello="world", acme="corp")
+    assert exc.match("got 2 unexpected options:")
 
 
 def test_defaults():
-    o = MyConfigurable(required_str='hello')
+    o = MyConfigurable(required_str="hello")
 
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.required_str == 'hello'
-    assert o.default_str == 'foo'
+    assert o.required_str == "hello"
+    assert o.default_str == "foo"
     assert o.integer is None
 
 
@@ -76,30 +76,30 @@ def test_str_type_factory():
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.required_str == '42'
-    assert o.default_str == 'foo'
+    assert o.required_str == "42"
+    assert o.default_str == "foo"
     assert o.integer is None
 
 
 def test_int_type_factory():
-    o = MyConfigurable(required_str='yo', default_str='bar', integer='42')
+    o = MyConfigurable(required_str="yo", default_str="bar", integer="42")
 
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.required_str == 'yo'
-    assert o.default_str == 'bar'
+    assert o.required_str == "yo"
+    assert o.default_str == "bar"
     assert o.integer == 42
 
 
 def test_bool_type_factory():
-    o = MyHarderConfigurable(required_str='yes', also_required='True')
+    o = MyHarderConfigurable(required_str="yes", also_required="True")
 
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.required_str == 'yes'
-    assert o.default_str == 'foo'
+    assert o.required_str == "yes"
+    assert o.default_str == "foo"
     assert o.integer is None
     assert o.also_required is True
 
@@ -110,22 +110,22 @@ def test_option_resolution_order():
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.required_str == 'kaboom'
-    assert o.default_str == 'foo'
+    assert o.required_str == "kaboom"
+    assert o.default_str == "foo"
     assert o.integer is None
 
 
 def test_option_positional():
-    o = MyConfigurableUsingPositionalOptions('1', '2', '3', required_str='hello')
+    o = MyConfigurableUsingPositionalOptions("1", "2", "3", required_str="hello")
 
     with inspect_node(o) as ni:
         assert not ni.partial
 
-    assert o.first == '1'
-    assert o.second == '2'
-    assert o.third == '3'
-    assert o.required_str == 'hello'
-    assert o.default_str == 'foo'
+    assert o.first == "1"
+    assert o.second == "2"
+    assert o.third == "3"
+    assert o.required_str == "hello"
+    assert o.default_str == "foo"
     assert o.integer is None
 
 

tests/config/test_methods.py

@@ -50,10 +50,7 @@ def test_define_with_decorator():
     calls = []
 
     def my_handler(*args, **kwargs):
-        calls.append((
-            args,
-            kwargs,
-        ))
+        calls.append((args, kwargs))
 
     Concrete = MethodBasedConfigurable(my_handler)
 
@@ -64,7 +61,7 @@ def test_define_with_decorator():
         assert ci.type == MethodBasedConfigurable
         assert ci.partial
 
-    t = Concrete('foo', bar='baz')
+    t = Concrete("foo", bar="baz")
 
     assert callable(t.handler)
     assert len(calls) == 0
@@ -75,15 +72,12 @@ def test_define_with_decorator():
 def test_late_binding_method_decoration():
     calls = []
 
-    @MethodBasedConfigurable(foo='foo')
+    @MethodBasedConfigurable(foo="foo")
     def Concrete(*args, **kwargs):
-        calls.append((
-            args,
-            kwargs,
-        ))
+        calls.append((args, kwargs))
 
     assert callable(Concrete.handler)
-    t = Concrete(bar='baz')
+    t = Concrete(bar="baz")
 
     assert callable(t.handler)
     assert len(calls) == 0
@@ -95,12 +89,9 @@ def test_define_with_argument():
     calls = []
 
     def concrete_handler(*args, **kwargs):
-        calls.append((
-            args,
-            kwargs,
-        ))
+        calls.append((args, kwargs))
 
-    t = MethodBasedConfigurable(concrete_handler, 'foo', bar='baz')
+    t = MethodBasedConfigurable(concrete_handler, "foo", bar="baz")
     assert callable(t.handler)
     assert len(calls) == 0
     t()
@@ -112,12 +103,9 @@ def test_define_with_inheritance():
 
     class Inheriting(MethodBasedConfigurable):
         def handler(self, *args, **kwargs):
-            calls.append((
-                args,
-                kwargs,
-            ))
+            calls.append((args, kwargs))
 
-    t = Inheriting('foo', bar='baz')
+    t = Inheriting("foo", bar="baz")
     assert callable(t.handler)
     assert len(calls) == 0
     t()
@@ -132,13 +120,10 @@ def test_inheritance_then_decorate():
 
     @Inheriting
     def Concrete(*args, **kwargs):
-        calls.append((
-            args,
-            kwargs,
-        ))
+        calls.append((args, kwargs))
 
     assert callable(Concrete.handler)
-    t = Concrete('foo', bar='baz')
+    t = Concrete("foo", bar="baz")
     assert callable(t.handler)
     assert len(calls) == 0
     t()

tests/config/test_methods_partial.py

@@ -12,11 +12,11 @@ class Bobby(Configurable):
 
     @ContextProcessor
     def think(self, context):
-        yield 'different'
+        yield "different"
 
     def __call__(self, think, *args, **kwargs):
-        self.handler('1', *args, **kwargs)
-        self.handler2('2', *args, **kwargs)
+        self.handler("1", *args, **kwargs)
+        self.handler2("2", *args, **kwargs)
 
 
 def test_partial():
@@ -40,7 +40,7 @@ def test_partial():
         assert len(ci.options) == 4
         assert len(ci.processors) == 1
         assert ci.partial
-        assert ci.partial[0] == (f1, )
+        assert ci.partial[0] == (f1,)
         assert not len(ci.partial[1])
 
     # instanciate a more complete partial instance ...
@@ -53,13 +53,10 @@ def test_partial():
         assert len(ci.options) == 4
         assert len(ci.processors) == 1
         assert ci.partial
-        assert ci.partial[0] == (
-            f1,
-            f2,
-        )
+        assert ci.partial[0] == (f1, f2)
         assert not len(ci.partial[1])
 
-    c = C('foo')
+    c = C("foo")
 
     with inspect_node(c) as ci:
         assert ci.type == Bobby

tests/config/test_processors.py

@@ -1,7 +1,7 @@
 from operator import attrgetter
 
 from bonobo.config import Configurable
-from bonobo.config.processors import ContextProcessor, resolve_processors, ContextCurrifier, use_context_processor
+from bonobo.config.processors import ContextCurrifier, ContextProcessor, resolve_processors, use_context_processor
 
 
 class CP1(Configurable):
@@ -11,11 +11,11 @@ class CP1(Configurable):
 
     @ContextProcessor
     def a(self):
-        yield 'this is A'
+        yield "this is A"
 
     @ContextProcessor
     def b(self, a):
-        yield a.upper()[:-1] + 'b'
+        yield a.upper()[:-1] + "b"
 
     def __call__(self, a, b):
         return a, b
@@ -46,20 +46,20 @@ class CP3(CP2):
 
 
 def get_all_processors_names(cls):
-    return list(map(attrgetter('__name__'), resolve_processors(cls)))
+    return list(map(attrgetter("__name__"), resolve_processors(cls)))
 
 
 def test_inheritance_and_ordering():
-    assert get_all_processors_names(CP1) == ['c', 'a', 'b']
-    assert get_all_processors_names(CP2) == ['c', 'a', 'b', 'f', 'e', 'd']
-    assert get_all_processors_names(CP3) == ['c', 'a', 'b', 'f', 'e', 'd', 'c', 'b']
+    assert get_all_processors_names(CP1) == ["c", "a", "b"]
+    assert get_all_processors_names(CP2) == ["c", "a", "b", "f", "e", "d"]
+    assert get_all_processors_names(CP3) == ["c", "a", "b", "f", "e", "d", "c", "b"]
 
 
 def test_setup_teardown():
     o = CP1()
     stack = ContextCurrifier(o)
     stack.setup()
-    assert o(*stack.args) == ('this is A', 'THIS IS b')
+    assert o(*stack.args) == ("this is A", "THIS IS b")
     stack.teardown()
 
 
@@ -71,4 +71,4 @@ def test_processors_on_func():
     def node(context):
         pass
 
-    assert get_all_processors_names(node) == ['cp']
+    assert get_all_processors_names(node) == ["cp"]

tests/config/test_services.py

@@ -4,11 +4,11 @@ import time
 import pytest
 
 from bonobo.config import Configurable, Container, Exclusive, Service, use
-from bonobo.config.services import validate_service_name, create_container
+from bonobo.config.services import create_container, validate_service_name
 from bonobo.util import get_name
 
 
-class PrinterInterface():
+class PrinterInterface:
     def print(self, *args):
         raise NotImplementedError()
 
@@ -18,46 +18,43 @@ class ConcretePrinter(PrinterInterface):
         self.prefix = prefix
 
     def print(self, *args):
-        return ';'.join((self.prefix, *args))
+        return ";".join((self.prefix, *args))
 
 
-SERVICES = Container(
-    printer0=ConcretePrinter(prefix='0'),
-    printer1=ConcretePrinter(prefix='1'),
-)
+SERVICES = Container(printer0=ConcretePrinter(prefix="0"), printer1=ConcretePrinter(prefix="1"))
 
 
 class MyServiceDependantConfigurable(Configurable):
-    printer = Service(PrinterInterface, )
+    printer = Service(PrinterInterface)
 
     def __call__(self, *args, printer: PrinterInterface):
         return printer.print(*args)
 
 
 def test_service_name_validator():
-    assert validate_service_name('foo') == 'foo'
-    assert validate_service_name('foo.bar') == 'foo.bar'
-    assert validate_service_name('Foo') == 'Foo'
-    assert validate_service_name('Foo.Bar') == 'Foo.Bar'
-    assert validate_service_name('Foo.a0') == 'Foo.a0'
+    assert validate_service_name("foo") == "foo"
+    assert validate_service_name("foo.bar") == "foo.bar"
+    assert validate_service_name("Foo") == "Foo"
+    assert validate_service_name("Foo.Bar") == "Foo.Bar"
+    assert validate_service_name("Foo.a0") == "Foo.a0"
 
     with pytest.raises(ValueError):
-        validate_service_name('foo.0')
+        validate_service_name("foo.0")
 
     with pytest.raises(ValueError):
-        validate_service_name('0.foo')
+        validate_service_name("0.foo")
 
 
 def test_service_dependency():
-    o = MyServiceDependantConfigurable(printer='printer0')
+    o = MyServiceDependantConfigurable(printer="printer0")
 
-    assert o('foo', 'bar', printer=SERVICES.get('printer0')) == '0;foo;bar'
-    assert o('bar', 'baz', printer=SERVICES.get('printer1')) == '1;bar;baz'
-    assert o('foo', 'bar', **SERVICES.kwargs_for(o)) == '0;foo;bar'
+    assert o("foo", "bar", printer=SERVICES.get("printer0")) == "0;foo;bar"
+    assert o("bar", "baz", printer=SERVICES.get("printer1")) == "1;bar;baz"
+    assert o("foo", "bar", **SERVICES.kwargs_for(o)) == "0;foo;bar"
 
 
 def test_service_dependency_unavailable():
-    o = MyServiceDependantConfigurable(printer='printer2')
+    o = MyServiceDependantConfigurable(printer="printer2")
     with pytest.raises(KeyError):
         SERVICES.kwargs_for(o)
 
@@ -72,15 +69,15 @@ class VCR:
 
 def test_exclusive():
     vcr = VCR()
-    vcr.append('hello')
+    vcr.append("hello")
 
     def record(prefix, vcr=vcr):
         with Exclusive(vcr):
             for i in range(5):
-                vcr.append(' '.join((prefix, str(i))))
+                vcr.append(" ".join((prefix, str(i))))
                 time.sleep(0.05)
 
-    threads = [threading.Thread(target=record, args=(str(i), )) for i in range(5)]
+    threads = [threading.Thread(target=record, args=(str(i),)) for i in range(5)]
 
     for thread in threads:
         thread.start()
@@ -90,8 +87,32 @@ def test_exclusive():
         thread.join()
 
     assert vcr.tape == [
-        'hello', '0 0', '0 1', '0 2', '0 3', '0 4', '1 0', '1 1', '1 2', '1 3', '1 4', '2 0', '2 1', '2 2', '2 3',
-        '2 4', '3 0', '3 1', '3 2', '3 3', '3 4', '4 0', '4 1', '4 2', '4 3', '4 4'
+        "hello",
+        "0 0",
+        "0 1",
+        "0 2",
+        "0 3",
+        "0 4",
+        "1 0",
+        "1 1",
+        "1 2",
+        "1 3",
+        "1 4",
+        "2 0",
+        "2 1",
+        "2 2",
+        "2 3",
+        "2 4",
+        "3 0",
+        "3 1",
+        "3 2",
+        "3 3",
+        "3 4",
+        "4 0",
+        "4 1",
+        "4 2",
+        "4 3",
+        "4 4",
     ]
 
 
@@ -100,28 +121,25 @@ def test_requires():
 
     services = Container(output=vcr.append)
 
-    @use('output')
+    @use("output")
     def append(out, x):
         out(x)
 
     svcargs = services.kwargs_for(append)
     assert len(svcargs) == 1
-    assert svcargs['output'] == vcr.append
+    assert svcargs["output"] == vcr.append
 
 
-@pytest.mark.parametrize('services', [None, {}])
+@pytest.mark.parametrize("services", [None, {}])
 def test_create_container_empty_values(services):
     c = create_container(services)
     assert len(c) == 2
-    assert 'fs' in c and get_name(c['fs']) == 'OSFS'
-    assert 'http' in c and get_name(c['http']) == 'requests'
+    assert "fs" in c and get_name(c["fs"]) == "OSFS"
+    assert "http" in c and get_name(c["http"]) == "requests"
 
 
 def test_create_container_override():
-    c = create_container({
-        'http': 'http',
-        'fs': 'fs',
-    })
+    c = create_container({"http": "http", "fs": "fs"})
     assert len(c) == 2
-    assert 'fs' in c and c['fs'] == 'fs'
-    assert 'http' in c and c['http'] == 'http'
+    assert "fs" in c and c["fs"] == "fs"
+    assert "http" in c and c["http"] == "http"

tests/examples/test_example_change_some_fields.py

@@ -5,22 +5,22 @@ from bonobo.config import use_raw_input
 from bonobo.execution.contexts import GraphExecutionContext
 from bonobo.util.bags import BagType
 
-Extracted = namedtuple('Extracted', ['id', 'name', 'value'])
-ExtractedBT = BagType('ExtractedBT', ['id', 'name', 'value'])
+Extracted = namedtuple("Extracted", ["id", "name", "value"])
+ExtractedBT = BagType("ExtractedBT", ["id", "name", "value"])
 
 
 def extract_nt():
-    yield Extracted(id=1, name='Guido', value='.py')
-    yield Extracted(id=2, name='Larry', value='.pl')
-    yield Extracted(id=3, name='Dennis', value='.c')
-    yield Extracted(id=4, name='Yukihiro', value='.rb')
+    yield Extracted(id=1, name="Guido", value=".py")
+    yield Extracted(id=2, name="Larry", value=".pl")
+    yield Extracted(id=3, name="Dennis", value=".c")
+    yield Extracted(id=4, name="Yukihiro", value=".rb")
 
 
 def extract_bt():
-    yield ExtractedBT(id=1, name='Guido', value='.py')
-    yield ExtractedBT(id=2, name='Larry', value='.pl')
-    yield ExtractedBT(id=3, name='Dennis', value='.c')
-    yield ExtractedBT(id=4, name='Yukihiro', value='.rb')
+    yield ExtractedBT(id=1, name="Guido", value=".py")
+    yield ExtractedBT(id=2, name="Larry", value=".pl")
+    yield ExtractedBT(id=3, name="Dennis", value=".c")
+    yield ExtractedBT(id=4, name="Yukihiro", value=".rb")
 
 
 def transform_using_args(id, name, value):
@@ -53,10 +53,18 @@ def test_execution():
     with GraphExecutionContext(graph) as context:
         context.run_until_complete()
 
-    assert result_args == [(2, 'Guido', 'guido.py'), (4, 'Larry', 'larry.pl'), (6, 'Dennis', 'dennis.c'),
-                           (8, 'Yukihiro', 'yukihiro.rb')]
+    assert result_args == [
+        (2, "Guido", "guido.py"),
+        (4, "Larry", "larry.pl"),
+        (6, "Dennis", "dennis.c"),
+        (8, "Yukihiro", "yukihiro.rb"),
+    ]
 
-    assert result_nt == [(1, 'GUIDO', '.py'), (2, 'LARRY', '.pl'), (3, 'DENNIS', '.c'), (4, 'YUKIHIRO', '.rb')]
+    assert result_nt == [(1, "GUIDO", ".py"), (2, "LARRY", ".pl"), (3, "DENNIS", ".c"), (4, "YUKIHIRO", ".rb")]
 
-    assert result_bt == [(2, 'Guido', 'guido.py'), (4, 'Larry', 'larry.pl'), (6, 'Dennis', 'dennis.c'),
-                         (8, 'Yukihiro', 'yukihiro.rb')]
+    assert result_bt == [
+        (2, "Guido", "guido.py"),
+        (4, "Larry", "larry.pl"),
+        (6, "Dennis", "dennis.c"),
+        (8, "Yukihiro", "yukihiro.rb"),
+    ]

tests/execution/contexts/test_execution_contexts_graph.py

@@ -1,14 +1,14 @@
 from bonobo import Graph
-from bonobo.constants import EMPTY, BEGIN, END
+from bonobo.constants import BEGIN, EMPTY, END
 from bonobo.execution.contexts import GraphExecutionContext
 
 
 def raise_an_error(*args, **kwargs):
-    raise Exception('Careful, man, there\'s a beverage here!')
+    raise Exception("Careful, man, there's a beverage here!")
 
 
 def raise_an_unrecoverrable_error(*args, **kwargs):
-    raise Exception('You are entering a world of pain!')
+    raise Exception("You are entering a world of pain!")
 
 
 def test_lifecycle_of_empty_graph():

tests/execution/contexts/test_execution_contexts_node.py

@@ -6,131 +6,131 @@ from bonobo import Graph
 from bonobo.constants import EMPTY
 from bonobo.execution.contexts.node import NodeExecutionContext, split_token
 from bonobo.execution.strategies import NaiveStrategy
-from bonobo.util.envelopes import F_NOT_MODIFIED, F_INHERIT
-from bonobo.util.testing import BufferingNodeExecutionContext, BufferingGraphExecutionContext
+from bonobo.util.envelopes import F_INHERIT, F_NOT_MODIFIED
+from bonobo.util.testing import BufferingGraphExecutionContext, BufferingNodeExecutionContext
 
 
 def test_node_string():
     def f():
-        return 'foo'
+        return "foo"
 
     with BufferingNodeExecutionContext(f) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 1
-        assert output[0] == ('foo', )
+        assert output[0] == ("foo",)
 
     def g():
-        yield 'foo'
-        yield 'bar'
+        yield "foo"
+        yield "bar"
 
     with BufferingNodeExecutionContext(g) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 2
-        assert output[0] == ('foo', )
-        assert output[1] == ('bar', )
+        assert output[0] == ("foo",)
+        assert output[1] == ("bar",)
 
 
 def test_node_bytes():
     def f():
-        return b'foo'
+        return b"foo"
 
     with BufferingNodeExecutionContext(f) as context:
         context.write_sync(EMPTY)
 
         output = context.get_buffer()
         assert len(output) == 1
-        assert output[0] == (b'foo', )
+        assert output[0] == (b"foo",)
 
     def g():
-        yield b'foo'
-        yield b'bar'
+        yield b"foo"
+        yield b"bar"
 
     with BufferingNodeExecutionContext(g) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 2
-        assert output[0] == (b'foo', )
-        assert output[1] == (b'bar', )
+        assert output[0] == (b"foo",)
+        assert output[1] == (b"bar",)
 
 
 def test_node_dict():
     def f():
-        return {'id': 1, 'name': 'foo'}
+        return {"id": 1, "name": "foo"}
 
     with BufferingNodeExecutionContext(f) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
         assert len(output) == 1
-        assert output[0] == ({'id': 1, 'name': 'foo'}, )
+        assert output[0] == ({"id": 1, "name": "foo"},)
 
     def g():
-        yield {'id': 1, 'name': 'foo'}
-        yield {'id': 2, 'name': 'bar'}
+        yield {"id": 1, "name": "foo"}
+        yield {"id": 2, "name": "bar"}
 
     with BufferingNodeExecutionContext(g) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
         assert len(output) == 2
-        assert output[0] == ({'id': 1, 'name': 'foo'}, )
-        assert output[1] == ({'id': 2, 'name': 'bar'}, )
+        assert output[0] == ({"id": 1, "name": "foo"},)
+        assert output[1] == ({"id": 2, "name": "bar"},)
 
 
 def test_node_dict_chained():
     strategy = NaiveStrategy(GraphExecutionContextType=BufferingGraphExecutionContext)
 
     def f():
-        return {'id': 1, 'name': 'foo'}
+        return {"id": 1, "name": "foo"}
 
     def uppercase_name(values):
-        return {**values, 'name': values['name'].upper()}
+        return {**values, "name": values["name"].upper()}
 
     graph = Graph(f, uppercase_name)
     context = strategy.execute(graph)
     output = context.get_buffer()
 
     assert len(output) == 1
-    assert output[0] == ({'id': 1, 'name': 'FOO'}, )
+    assert output[0] == ({"id": 1, "name": "FOO"},)
 
     def g():
-        yield {'id': 1, 'name': 'foo'}
-        yield {'id': 2, 'name': 'bar'}
+        yield {"id": 1, "name": "foo"}
+        yield {"id": 2, "name": "bar"}
 
     graph = Graph(g, uppercase_name)
     context = strategy.execute(graph)
     output = context.get_buffer()
 
     assert len(output) == 2
-    assert output[0] == ({'id': 1, 'name': 'FOO'}, )
-    assert output[1] == ({'id': 2, 'name': 'BAR'}, )
+    assert output[0] == ({"id": 1, "name": "FOO"},)
+    assert output[1] == ({"id": 2, "name": "BAR"},)
 
 
 def test_node_tuple():
     def f():
-        return 'foo', 'bar'
+        return "foo", "bar"
 
     with BufferingNodeExecutionContext(f) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 1
-        assert output[0] == ('foo', 'bar')
+        assert output[0] == ("foo", "bar")
 
     def g():
-        yield 'foo', 'bar'
-        yield 'foo', 'baz'
+        yield "foo", "bar"
+        yield "foo", "baz"
 
     with BufferingNodeExecutionContext(g) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 2
-        assert output[0] == ('foo', 'bar')
-        assert output[1] == ('foo', 'baz')
+        assert output[0] == ("foo", "bar")
+        assert output[1] == ("foo", "baz")
 
 
 def test_node_tuple_chained():
@@ -140,50 +140,50 @@ def test_node_tuple_chained():
         return tuple(map(str.upper, args))
 
     def f():
-        return 'foo', 'bar'
+        return "foo", "bar"
 
     graph = Graph(f, uppercase)
     context = strategy.execute(graph)
     output = context.get_buffer()
 
     assert len(output) == 1
-    assert output[0] == ('FOO', 'BAR')
+    assert output[0] == ("FOO", "BAR")
 
     def g():
-        yield 'foo', 'bar'
-        yield 'foo', 'baz'
+        yield "foo", "bar"
+        yield "foo", "baz"
 
     graph = Graph(g, uppercase)
     context = strategy.execute(graph)
     output = context.get_buffer()
 
     assert len(output) == 2
-    assert output[0] == ('FOO', 'BAR')
-    assert output[1] == ('FOO', 'BAZ')
+    assert output[0] == ("FOO", "BAR")
+    assert output[1] == ("FOO", "BAZ")
 
 
 def test_node_tuple_dict():
     def f():
-        return 'foo', 'bar', {'id': 1}
+        return "foo", "bar", {"id": 1}
 
     with BufferingNodeExecutionContext(f) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 1
-        assert output[0] == ('foo', 'bar', {'id': 1})
+        assert output[0] == ("foo", "bar", {"id": 1})
 
     def g():
-        yield 'foo', 'bar', {'id': 1}
-        yield 'foo', 'baz', {'id': 2}
+        yield "foo", "bar", {"id": 1}
+        yield "foo", "baz", {"id": 2}
 
     with BufferingNodeExecutionContext(g) as context:
         context.write_sync(EMPTY)
         output = context.get_buffer()
 
         assert len(output) == 2
-        assert output[0] == ('foo', 'bar', {'id': 1})
-        assert output[1] == ('foo', 'baz', {'id': 2})
+        assert output[0] == ("foo", "bar", {"id": 1})
+        assert output[1] == ("foo", "baz", {"id": 2})
 
 
 def test_node_lifecycle_natural():
@@ -229,9 +229,9 @@ def test_node_lifecycle_with_kill():
 
 def test_split_token():
     with pytest.deprecated_call():
-        assert split_token(('foo', 'bar')) == (set(), ('foo', 'bar'))
+        assert split_token(("foo", "bar")) == (set(), ("foo", "bar"))
         assert split_token(()) == (set(), ())
-        assert split_token('') == (set(), ('', ))
+        assert split_token("") == (set(), ("",))
 
 
 def test_split_token_duplicate():
@@ -247,17 +247,17 @@ def test_split_token_duplicate():
 def test_split_token_not_modified():
     with pytest.deprecated_call():
         with pytest.raises(ValueError):
-            split_token((F_NOT_MODIFIED, 'foo', 'bar'))
+            split_token((F_NOT_MODIFIED, "foo", "bar"))
         with pytest.raises(ValueError):
             split_token((F_NOT_MODIFIED, F_INHERIT))
         with pytest.raises(ValueError):
             split_token((F_INHERIT, F_NOT_MODIFIED))
         assert split_token(F_NOT_MODIFIED) == ({F_NOT_MODIFIED}, ())
-        assert split_token((F_NOT_MODIFIED, )) == ({F_NOT_MODIFIED}, ())
+        assert split_token((F_NOT_MODIFIED,)) == ({F_NOT_MODIFIED}, ())
 
 
 def test_split_token_inherit():
     with pytest.deprecated_call():
         assert split_token(F_INHERIT) == ({F_INHERIT}, ())
-        assert split_token((F_INHERIT, )) == ({F_INHERIT}, ())
-        assert split_token((F_INHERIT, 'foo', 'bar')) == ({F_INHERIT}, ('foo', 'bar'))
+        assert split_token((F_INHERIT,)) == ({F_INHERIT}, ())
+        assert split_token((F_INHERIT, "foo", "bar")) == ({F_INHERIT}, ("foo", "bar"))

tests/execution/test_events.py

@@ -6,9 +6,9 @@ from bonobo.execution import events
 def test_names():
     # This test looks useless, but as it's becoming the pliugin API, I want to make sure that nothing changes here, or
     # notice it otherwise.
-    for name in 'start', 'started', 'tick', 'stop', 'stopped', 'kill':
+    for name in "start", "started", "tick", "stop", "stopped", "kill":
         event_name = getattr(events, name.upper())
-        assert event_name == '.'.join(('execution', name))
+        assert event_name == ".".join(("execution", name))
 
 
 def test_event_object():

tests/ext/test_ods.py

@@ -14,16 +14,11 @@ class ResponseMock:
             return {}
         else:
             self.count += 1
-            return {
-                'records': self.json_value,
-            }
+            return {"records": self.json_value}
 
 
 def test_read_from_opendatasoft_api():
-    extract = OpenDataSoftAPI(dataset='test-a-set')
-    with patch('requests.get', return_value=ResponseMock([
-        {'fields': {'foo': 'bar'}},
-        {'fields': {'foo': 'zab'}},
-    ])):
-        for line in extract('http://example.com/', ValueHolder(0)):
-            assert 'foo' in line
+    extract = OpenDataSoftAPI(dataset="test-a-set")
+    with patch("requests.get", return_value=ResponseMock([{"fields": {"foo": "bar"}}, {"fields": {"foo": "zab"}}])):
+        for line in extract("http://example.com/", ValueHolder(0)):
+            assert "foo" in line

tests/features/test_inherit.py

@@ -1,27 +1,24 @@
 from bonobo.util.envelopes import AppendingEnvelope
 from bonobo.util.testing import BufferingNodeExecutionContext
 
-messages = [
-    ('Hello', ),
-    ('Goodbye', ),
-]
+messages = [("Hello",), ("Goodbye",)]
 
 
 def append(*args):
-    return AppendingEnvelope('!')
+    return AppendingEnvelope("!")
 
 
 def test_inherit():
     with BufferingNodeExecutionContext(append) as context:
         context.write_sync(*messages)
 
-    assert context.get_buffer() == list(map(lambda x: x + ('!', ), messages))
+    assert context.get_buffer() == list(map(lambda x: x + ("!",), messages))
 
 
 def test_inherit_bag_tuple():
     with BufferingNodeExecutionContext(append) as context:
-        context.set_input_fields(['message'])
+        context.set_input_fields(["message"])
         context.write_sync(*messages)
 
-    assert context.get_output_fields() == ('message', '0')
-    assert context.get_buffer() == list(map(lambda x: x + ('!', ), messages))
+    assert context.get_output_fields() == ("message", "0")
+    assert context.get_buffer() == list(map(lambda x: x + ("!",), messages))