[stdlib] Adds Update(...) and FixedWindow(...) the the standard nodes provided with bonobo.

benchmarks/parameters.py

@@ -14,31 +14,43 @@ k3 1.353256585993222
 import json
 import timeit
 
+
 def j1(d):
     return {'prepend': 'foo', **d, 'append': 'bar'}
 
+
 def k1(**d):
     return {'prepend': 'foo', **d, 'append': 'bar'}
 
+
 def j2(d):
     return {**d}
 
+
 def k2(**d):
     return {**d}
 
+
 def j3(d):
     return None
 
+
 def k3(**d):
     return None
 
+
 if __name__ == '__main__':
     import timeit
 
     with open('person.json') as f:
         json_data = json.load(f)
 
-
-    for i in 1,2,3:
-        print('j{}'.format(i), timeit.timeit("j{}({!r})".format(i, json_data), setup="from __main__ import j{}".format(i)))
-        print('k{}'.format(i), timeit.timeit("k{}(**{!r})".format(i, json_data), setup="from __main__ import k{}".format(i)))
+    for i in 1, 2, 3:
+        print(
+            'j{}'.format(i),
+            timeit.timeit("j{}({!r})".format(i, json_data), setup="from __main__ import j{}".format(i))
+        )
+        print(
+            'k{}'.format(i),
+            timeit.timeit("k{}(**{!r})".format(i, json_data), setup="from __main__ import k{}".format(i))
+        )

bonobo/_api.py

@@ -1,6 +1,26 @@
 from bonobo.execution.strategies import create_strategy
-from bonobo.nodes import CsvReader, CsvWriter, FileReader, FileWriter, Filter, JsonReader, JsonWriter, Limit, \
-    PickleReader, PickleWriter, PrettyPrinter, RateLimited, Tee, arg0_to_kwargs, count, identity, kwargs_to_arg0, noop
+from bonobo.nodes import (
+    CsvReader,
+    CsvWriter,
+    FileReader,
+    FileWriter,
+    Filter,
+    FixedWindow,
+    JsonReader,
+    JsonWriter,
+    Limit,
+    PickleReader,
+    PickleWriter,
+    PrettyPrinter,
+    RateLimited,
+    Tee,
+    Update,
+    arg0_to_kwargs,
+    count,
+    identity,
+    kwargs_to_arg0,
+    noop,
+)
 from bonobo.nodes import LdjsonReader, LdjsonWriter
 from bonobo.structs import Bag, ErrorBag, Graph, Token
 from bonobo.util import get_name
@@ -25,8 +45,10 @@ def register_graph_api(x, __all__=__all__):
     required_parameters = {'plugins', 'services', 'strategy'}
     assert 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))
+        parameters
+    ) == required_parameters, 'Graph api functions must define the following parameters: ' + ', '.join(
+        sorted(required_parameters)
+    )
 
     return register_api(x, __all__=__all__)
 
@@ -149,6 +171,7 @@ register_api_group(
     FileReader,
     FileWriter,
     Filter,
+    FixedWindow,
     JsonReader,
     JsonWriter,
     LdjsonReader,
@@ -159,6 +182,7 @@ register_api_group(
     PrettyPrinter,
     RateLimited,
     Tee,
+    Update,
     arg0_to_kwargs,
     count,
     identity,

bonobo/contrib/django/commands.py

@@ -22,9 +22,7 @@ class ETLCommand(BaseCommand):
     create_or_update = staticmethod(create_or_update)
 
     def create_parser(self, prog_name, subcommand):
-        return bonobo.get_argument_parser(
-            super().create_parser(prog_name, subcommand)
-        )
+        return bonobo.get_argument_parser(super().create_parser(prog_name, subcommand))
 
     def get_graph(self, *args, **options):
         def not_implemented():

bonobo/contrib/jupyter/__init__.py

@@ -2,12 +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__ = [

bonobo/execution/strategies/executor.py

@@ -10,6 +10,7 @@ from bonobo.util import get_name
 
 logger = logging.getLogger(__name__)
 
+
 class ExecutorStrategy(Strategy):
     """
     Strategy based on a concurrent.futures.Executor subclass (or similar interface).

bonobo/nodes/basics.py

@@ -4,16 +4,17 @@ import itertools
 from bonobo import settings
 from bonobo.config import Configurable, Option
 from bonobo.config.processors import ContextProcessor
+from bonobo.constants import NOT_MODIFIED
 from bonobo.structs.bags import Bag
 from bonobo.util.objects import ValueHolder
 from bonobo.util.term import CLEAR_EOL
 
-from bonobo.constants import NOT_MODIFIED
-
 __all__ = [
+    'FixedWindow',
     'Limit',
     'PrettyPrinter',
     'Tee',
+    'Update',
     'arg0_to_kwargs',
     'count',
     'identity',
@@ -128,3 +129,49 @@ def kwargs_to_arg0(**row):
     :return: bonobo.Bag
     """
     return Bag(row)
+
+
+def Update(*consts, **kwconsts):
+    """
+    Transformation factory to update a stream with constant values, by appending to args and updating kwargs.
+
+    :param consts: what to append to the input stream args
+    :param kwconsts: what to use to update input stream kwargs
+    :return: function
+
+    """
+
+    def update(*args, **kwargs):
+        nonlocal consts, kwconsts
+        return (*args, *consts, {**kwargs, **kwconsts})
+
+    update.__name__ = 'Update({})'.format(Bag.format_args(*consts, **kwconsts))
+
+    return update
+
+
+class FixedWindow(Configurable):
+    """
+    Transformation factory to create fixed windows of inputs, as lists.
+
+    For example, if the input is successively 1, 2, 3, 4, etc. and you pass it through a ``FixedWindow(2)``, you'll get
+    lists of elements 2 by 2: [1, 2], [3, 4], ...
+
+    """
+
+    length = Option(int, positional=True)  # type: int
+
+    @ContextProcessor
+    def buffer(self, context):
+        buffer = yield ValueHolder([])
+        if len(buffer):
+            context.send(Bag(buffer.get()))
+
+    def call(self, buffer, x):
+        buffer.append(x)
+        if len(buffer) >= self.length:
+            yield buffer.get()
+            buffer.set([])
+
+
+

bonobo/plugins/jupyter.py

@@ -30,6 +30,4 @@ class JupyterOutputPlugin(Plugin):
         IPython.core.display.display(self.widget)
 
     def tick(self, event):
-        self.widget.value = [
-            event.context[i].as_dict() for i in event.context.graph.topologically_sorted_indexes
-        ]
+        self.widget.value = [event.context[i].as_dict() for i in event.context.graph.topologically_sorted_indexes]

bonobo/structs/bags.py

@@ -1,7 +1,7 @@
 import itertools
 
-from bonobo.structs.tokens import Token
 from bonobo.constants import INHERIT_INPUT, LOOPBACK
+from bonobo.structs.tokens import Token
 
 __all__ = [
     'Bag',
@@ -36,6 +36,10 @@ class Bag:
 
     default_flags = ()
 
+    @staticmethod
+    def format_args(*args, **kwargs):
+        return ', '.join(itertools.chain(map(repr, args), ('{}={!r}'.format(k, v) for k, v in kwargs.items())))
+
     def __new__(cls, *args, _flags=None, _parent=None, **kwargs):
         # Handle the special case where we call Bag's constructor with only one bag or token as argument.
         if len(args) == 1 and len(kwargs) == 0:
@@ -86,6 +90,9 @@ class Bag:
             self._args = args
             self._kwargs = kwargs
 
+    def __repr__(self):
+        return 'Bag({})'.format(Bag.format_args(*self.args, **self.kwargs))
+
     @property
     def args(self):
         if self._parent is None:
@@ -141,7 +148,7 @@ class Bag:
 
     @classmethod
     def inherit(cls, *args, **kwargs):
-        return cls(*args, _flags=(INHERIT_INPUT, ), **kwargs)
+        return cls(*args, _flags=(INHERIT_INPUT,), **kwargs)
 
     def __eq__(self, other):
         # XXX there are overlapping cases, but this is very handy for now. Let's think about it later.
@@ -169,19 +176,9 @@ class Bag:
 
         return len(self.args) == 1 and not self.kwargs and self.args[0] == other
 
-    def __repr__(self):
-        return '<{} ({})>'.format(
-            type(self).__name__, ', '.join(
-                itertools.chain(
-                    map(repr, self.args),
-                    ('{}={}'.format(k, repr(v)) for k, v in self.kwargs.items()),
-                )
-            )
-        )
-
 
 class LoopbackBag(Bag):
-    default_flags = (LOOPBACK, )
+    default_flags = (LOOPBACK,)
 
 
 class ErrorBag(Bag):

bonobo/util/objects.py

@@ -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

tests/nodes/test_basics.py

@@ -1,3 +1,4 @@
+from operator import methodcaller
 from unittest.mock import MagicMock
 
 import pytest
@@ -5,6 +6,7 @@ import pytest
 import bonobo
 from bonobo.config.processors import ContextCurrifier
 from bonobo.constants import NOT_MODIFIED
+from bonobo.util.testing import BufferingNodeExecutionContext
 
 
 def test_count():
@@ -72,3 +74,38 @@ def test_tee():
 
 def test_noop():
     assert bonobo.noop(1, 2, 3, 4, foo='bar') == NOT_MODIFIED
+
+
+def test_update():
+    with BufferingNodeExecutionContext(bonobo.Update('a', k=True)) as context:
+        context.write_sync('a', ('a', {'b': 1}), ('b', {'k': False}))
+    assert context.get_buffer() == [
+        bonobo.Bag('a', 'a', k=True),
+        bonobo.Bag('a', 'a', b=1, k=True),
+        bonobo.Bag('b', 'a', k=True),
+    ]
+    assert context.name == "Update('a', k=True)"
+
+
+def test_fixedwindow():
+    with BufferingNodeExecutionContext(bonobo.FixedWindow(2)) as context:
+        context.write_sync(*range(10))
+    assert context.get_buffer() == [[0, 1], [2, 3], [4, 5], [6, 7], [8, 9]]
+
+    with BufferingNodeExecutionContext(bonobo.FixedWindow(2)) as context:
+        context.write_sync(*range(9))
+    assert context.get_buffer() == [[0, 1], [2, 3], [4, 5], [6, 7], [8]]
+
+    with BufferingNodeExecutionContext(bonobo.FixedWindow(1)) as context:
+        context.write_sync(*range(3))
+    assert context.get_buffer() == [[0], [1], [2]]
+
+
+def test_methodcaller():
+    with BufferingNodeExecutionContext(methodcaller('swapcase')) as context:
+        context.write_sync('aaa', 'bBb', 'CcC')
+    assert context.get_buffer() == ['AAA', 'BbB', 'cCc']
+
+    with BufferingNodeExecutionContext(methodcaller('zfill', 5)) as context:
+        context.write_sync('a', 'bb', 'ccc')
+    assert context.get_buffer() == ['0000a', '000bb', '00ccc']

tests/structs/test_bags.py

@@ -159,7 +159,7 @@ def test_eq_operator_dict():
 
 def test_repr():
     bag = Bag('a', a=1)
-    assert repr(bag) == "<Bag ('a', a=1)>"
+    assert repr(bag) == "Bag('a', a=1)"
 
 
 def test_iterator():