From 8b63b0bf447bafa8e0b4e689343dd2b754301913 Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Thu, 29 Dec 2016 17:27:06 +0100
Subject: [PATCH 1/6] doc update and better versionning method

---
 .gitignore                            |   1 +
 Makefile                              |   2 +-
 bonobo/__init__.py                    |  13 +--
 bonobo/_version.py                    |   1 +
 docs/_static/custom.css               |   3 +
 docs/_static/graphs.css               |   2 +
 docs/guide/crawlers.rst               |  33 +++++++
 docs/guide/index.rst                  |   6 +-
 docs/guide/purity.rst                 | 128 ++++++++++++++++++++++++++
 docs/reference/bonobo.ext.console.rst |  22 -----
 docs/reference/bonobo.ext.jupyter.rst |  30 ------
 docs/reference/bonobo.ext.rst         |  46 ---------
 docs/tutorial/basics.rst              |   5 +-
 setup.py                              |  18 +++-
 version.txt                           |   1 -
 15 files changed, 197 insertions(+), 114 deletions(-)
 create mode 100644 bonobo/_version.py
 create mode 100644 docs/_static/custom.css
 create mode 100644 docs/_static/graphs.css
 create mode 100644 docs/guide/crawlers.rst
 create mode 100644 docs/guide/purity.rst
 delete mode 100644 docs/reference/bonobo.ext.console.rst
 delete mode 100644 docs/reference/bonobo.ext.jupyter.rst
 delete mode 100644 docs/reference/bonobo.ext.rst
 delete mode 100644 version.txt

diff --git a/.gitignore b/.gitignore
index c731916..da70ff2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@
 *.py[cod]
 *.so
 *.spec
+.*.sw?
 .Python
 .cache
 .coverage
diff --git a/Makefile b/Makefile
index c580632..e84f7a5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2016-12-28 15:50:31.026587
+# Updated at 2016-12-29 17:04:15.403353
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
diff --git a/bonobo/__init__.py b/bonobo/__init__.py
index d70e30a..685e08d 100644
--- a/bonobo/__init__.py
+++ b/bonobo/__init__.py
@@ -19,21 +19,15 @@
     See the License for the specific language governing permissions and
     limitations under the License.
 """
-import os
 import sys
 
+assert (sys.version_info >= (3, 5)), 'Python 3.5+ is required to use Bonobo.'
+
+from ._version import __version__
 from .core import *
 from .io import CsvReader, CsvWriter, FileReader, FileWriter, JsonReader, JsonWriter
 from .util import *
 
-PY35 = (sys.version_info >= (3, 5))
-
-assert PY35, 'Python 3.5+ is required to use Bonobo.'
-
-# Version infos
-with open(os.path.realpath(os.path.join(os.path.dirname(__file__), '../version.txt'))) as f:
-    __version__ = f.read().strip()
-
 __all__ = [
     'Bag',
     'CsvReader',
@@ -47,6 +41,7 @@ __all__ = [
     'NaiveStrategy',
     'ProcessPoolExecutorStrategy',
     'ThreadPoolExecutorStrategy',
+    '__version__',
     'console_run',
     'head',
     'inject',
diff --git a/bonobo/_version.py b/bonobo/_version.py
new file mode 100644
index 0000000..8ce9b36
--- /dev/null
+++ b/bonobo/_version.py
@@ -0,0 +1 @@
+__version__ = '0.1.3'
diff --git a/docs/_static/custom.css b/docs/_static/custom.css
new file mode 100644
index 0000000..f658da9
--- /dev/null
+++ b/docs/_static/custom.css
@@ -0,0 +1,3 @@
+svg {
+    border: 2px solid green
+}
\ No newline at end of file
diff --git a/docs/_static/graphs.css b/docs/_static/graphs.css
new file mode 100644
index 0000000..873f3d6
--- /dev/null
+++ b/docs/_static/graphs.css
@@ -0,0 +1,2 @@
+.node {
+}
\ No newline at end of file
diff --git a/docs/guide/crawlers.rst b/docs/guide/crawlers.rst
new file mode 100644
index 0000000..7a9a181
--- /dev/null
+++ b/docs/guide/crawlers.rst
@@ -0,0 +1,33 @@
+Web crawlers with Bonobo
+========================
+
+.. todo:: Bonobo-Selenium is at a very alpha stage, and things will change. This section is here to give a brief
+          overview but is neither complete nor definitive.
+
+Writing web crawlers with Bonobo and Selenium is easy.
+
+First, install **bonobo-selenium**:
+
+.. code-block:: shell-session
+
+    $ pip install bonobo-selenium
+
+The idea is to have one callable crawl one thing and delegate drill downs to callables further away in the chain.
+
+An example chain could be:
+
+.. graphviz::
+
+    digraph {
+        rankdir = LR;
+        login -> paginate -> list -> details -> "ExcelWriter(...)";
+    }
+
+Where each step would do the following:
+
+* `login()` is in charge to open an authenticated session in the browser.
+* `paginate()` open each page of a fictive list and pass it to next.
+* `list()` take every list item and yield it.
+* `details()` extract the data you're interested in.
+* ... and the writer saves it somewhere.
+
diff --git a/docs/guide/index.rst b/docs/guide/index.rst
index ebd0d17..99ae56f 100644
--- a/docs/guide/index.rst
+++ b/docs/guide/index.rst
@@ -1,4 +1,8 @@
 Guides
 ======
 
-.. todo:: write the fucking doc!
+.. toctree::
+    :maxdepth: 2
+
+    purity
+    crawlers
diff --git a/docs/guide/purity.rst b/docs/guide/purity.rst
new file mode 100644
index 0000000..1995284
--- /dev/null
+++ b/docs/guide/purity.rst
@@ -0,0 +1,128 @@
+Pure components and space complexity
+====================================
+
+The nature of components, and how the data flow from one to another, make them not so easy to write correctly.
+Hopefully, with a few hints, you will be able to understand why and how they should be written.
+
+The major problem we have is that one message can go through more than one component, and at the same time. If you
+wanna be safe, you tend to :func:`copy.copy()` everything between two calls to two different components, but that
+will mean that a lot of useless memory space would be taken for copies that are never modified.
+
+Instead of that, we chosed the oposite: copies are never made, and you should not modify in place the inputs of your
+component before yielding them, and that mostly means that you want to recreate dicts and lists before yielding (or
+returning) them. Numeric values, strings and tuples being immutable in python, modifying a variable of one of those
+type will already return a different instance.
+
+Numbers
+=======
+
+You can't be wrong with numbers. All of the following are correct.
+
+.. code-block:: python
+
+    def do_your_number_thing(n: int) -> int:
+        return n
+
+    def do_your_number_thing(n: int) -> int:
+        yield n
+
+    def do_your_number_thing(n: int) -> int:
+        return n + 1
+
+    def do_your_number_thing(n: int) -> int:
+        yield n + 1
+
+    def do_your_number_thing(n: int) -> int:
+        # correct, but bad style
+        n += 1
+        return n
+
+    def do_your_number_thing(n: int) -> int:
+        # correct, but bad style
+        n += 1
+        yield n
+
+The same is true with other numeric types, so don't be shy. Operate like crazy, my friend.
+
+Tuples
+======
+
+Tuples are immutable, so you risk nothing.
+
+.. code-block:: python
+
+    def do_your_tuple_thing(t: tuple) -> tuple:
+        return ('foo', ) + t
+
+    def do_your_tuple_thing(t: tuple) -> tuple:
+        return t + ('bar', )
+
+    def do_your_tuple_thing(t: tuple) -> tuple:
+        # correct, but bad style
+        t += ('baaaz', )
+        return t
+
+Strings
+=======
+
+You know the drill, strings are immutable, blablabla ... Examples left as an exercise for the reader.
+
+Dicts
+=====
+
+So, now it gets interesting. Dicts are mutable. It means that you can mess things up badly here if you're not cautious.
+
+For example, doing the following may cause unexpected problems:
+
+.. code-block:: python
+
+    def mutate_my_dict_like_crazy(d: dict) -> dict:
+        # Bad! Don't do that!
+        d.update({
+            'foo': compute_something()
+        })
+        # Still bad! Don't mutate the dict!
+        d['bar']: compute_anotherthing()
+        return d
+
+The problem is easy to understand: as **Bonobo** won't make copies of your dict, the same dict will be passed along the
+transformation graph, and mutations will be seen in components downwards the output, but also upward. Let's see
+a more obvious example of something you should not do:
+
+.. code-block:: python
+
+    def mutate_my_dict_and_yield() -> dict:
+        d = {}
+        for i in range(100):
+            # Bad! Don't do that!
+            d['index'] = i
+            yield d
+
+Here, the same dict is yielded in each iteration, and its state when the next component in chain is called is undetermined.
+
+Now let's see how to do it correctly:
+
+.. code-block:: python
+
+    def new_dicts_like_crazy(d: dict) -> dict:
+        # Creating a new dict is correct.
+        return {
+            **d,
+            'foo': compute_something(),
+            'bar': compute_anotherthing(),
+        }
+
+    def new_dict_and_yield() -> dict:
+        d = {}
+        for i in range(100):
+            # Different dict each time.
+            yield {
+                'index': i
+            }
+
+I hear you think «Yeah, but if I create like millions of dicts ...». The answer is simple. Using dicts like this will
+create a lot, but also free a lot because as soon as all the future components that take this dict as input are done,
+the dict will be garbage collected. Youplaboum!
+
+
+
diff --git a/docs/reference/bonobo.ext.console.rst b/docs/reference/bonobo.ext.console.rst
deleted file mode 100644
index 4385466..0000000
--- a/docs/reference/bonobo.ext.console.rst
+++ /dev/null
@@ -1,22 +0,0 @@
-bonobo.ext.console package
-==========================
-
-Submodules
-----------
-
-bonobo.ext.console.plugin module
---------------------------------
-
-.. automodule:: bonobo.ext.console.plugin
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-
-Module contents
----------------
-
-.. automodule:: bonobo.ext.console
-    :members:
-    :undoc-members:
-    :show-inheritance:
diff --git a/docs/reference/bonobo.ext.jupyter.rst b/docs/reference/bonobo.ext.jupyter.rst
deleted file mode 100644
index c695678..0000000
--- a/docs/reference/bonobo.ext.jupyter.rst
+++ /dev/null
@@ -1,30 +0,0 @@
-bonobo.ext.jupyter package
-==========================
-
-Submodules
-----------
-
-bonobo.ext.jupyter.plugin module
---------------------------------
-
-.. automodule:: bonobo.ext.jupyter.plugin
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-bonobo.ext.jupyter.widget module
---------------------------------
-
-.. automodule:: bonobo.ext.jupyter.widget
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-
-Module contents
----------------
-
-.. automodule:: bonobo.ext.jupyter
-    :members:
-    :undoc-members:
-    :show-inheritance:
diff --git a/docs/reference/bonobo.ext.rst b/docs/reference/bonobo.ext.rst
deleted file mode 100644
index 63327ef..0000000
--- a/docs/reference/bonobo.ext.rst
+++ /dev/null
@@ -1,46 +0,0 @@
-bonobo.ext package
-==================
-
-Subpackages
------------
-
-.. toctree::
-
-    bonobo.ext.console
-    bonobo.ext.jupyter
-
-Submodules
-----------
-
-bonobo.ext.couchdb_ module
---------------------------
-
-.. automodule:: bonobo.ext.couchdb_
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-bonobo.ext.opendatasoft module
-------------------------------
-
-.. automodule:: bonobo.ext.opendatasoft
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-bonobo.ext.selenium module
---------------------------
-
-.. automodule:: bonobo.ext.selenium
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-
-Module contents
----------------
-
-.. automodule:: bonobo.ext
-    :members:
-    :undoc-members:
-    :show-inheritance:
diff --git a/docs/tutorial/basics.rst b/docs/tutorial/basics.rst
index ad507b7..3b1b989 100644
--- a/docs/tutorial/basics.rst
+++ b/docs/tutorial/basics.rst
@@ -58,7 +58,10 @@ Let's chain the three components together and run the transformation:
 
     digraph {
         rankdir = LR;
-        "generate_data" -> "uppercase" -> "output";
+        stylesheet = "../_static/graphs.css";
+
+        BEGIN [shape="point"];
+        BEGIN -> "generate_data" -> "uppercase" -> "output";
     }
 
 We use the :func:`bonobo.run` helper that hides the underlying object composition necessary to actually run the
diff --git a/setup.py b/setup.py
index 624fd3f..a19e5bd 100644
--- a/setup.py
+++ b/setup.py
@@ -1,8 +1,11 @@
 # This file is autogenerated by edgy.project code generator.
 # All changes will be overwritten.
 
+import os
 from setuptools import setup, find_packages
 
+root_dir = os.path.dirname(os.path.abspath(__file__))
+
 tolines = lambda c: list(filter(None, map(lambda s: s.strip(), c.split('\n'))))
 
 
@@ -12,10 +15,19 @@ def read(filename, flt=None):
         return flt(content) if callable(flt) else content
 
 
+# Py3 compatibility hacks, borrowed from IPython.
 try:
-    version = read('version.txt')
-except:  # pylint: disable=bare-except
-    version = 'dev'
+    execfile
+except NameError:
+
+    def execfile(fname, globs, locs=None):
+        locs = locs or globs
+        exec(compile(open(fname).read(), fname, "exec"), globs, locs)
+
+
+version_ns = {}
+execfile(os.path.join(root_dir, 'bonobo/_version.py'), version_ns)
+version = version_ns.get('__version__', 'dev')
 
 setup(
     name='bonobo',
diff --git a/version.txt b/version.txt
deleted file mode 100644
index d917d3e..0000000
--- a/version.txt
+++ /dev/null
@@ -1 +0,0 @@
-0.1.2

From a4c051963e49c84cd0bad65578180f081ca4d94c Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Thu, 29 Dec 2016 17:34:14 +0100
Subject: [PATCH 2/6] version

---
 Makefile     |  4 ++--
 docs/conf.py |  3 +--
 setup.py     | 52 ++++++++++++++++++++++++++--------------------------
 3 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/Makefile b/Makefile
index e84f7a5..a26569b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2016-12-29 17:04:15.403353
+# Updated at 2016-12-29 17:33:45.585172
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
@@ -41,7 +41,7 @@ clean:
 # Setup the local virtualenv, or use the one provided by the current environment.
 $(VIRTUAL_ENV):
 	virtualenv -p $(PYTHON) $(VIRTUAL_ENV)
-	$(PIP) install -U pip\>=8.1.2,\<9 wheel\>=0.29,\<1.0
+	$(PIP) install -U pip\>=9,\<10 wheel\>=0.29,\<1.0
 	ln -fs $(VIRTUAL_ENV)/bin/activate activate-$(PYTHON_BASENAME)
 
 lint: install-dev
diff --git a/docs/conf.py b/docs/conf.py
index 80d0660..8fb96ed 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -42,8 +42,7 @@ author = 'Romain Dorgueil'
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
-version = bonobo.__version__
-release = bonobo.__version__
+version = release = bonobo.__version__
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.py b/setup.py
index a19e5bd..f0d6724 100644
--- a/setup.py
+++ b/setup.py
@@ -8,47 +8,47 @@ root_dir = os.path.dirname(os.path.abspath(__file__))
 
 tolines = lambda c: list(filter(None, map(lambda s: s.strip(), c.split('\n'))))
 
-
 def read(filename, flt=None):
     with open(filename) as f:
         content = f.read().strip()
         return flt(content) if callable(flt) else content
 
-
 # Py3 compatibility hacks, borrowed from IPython.
 try:
     execfile
 except NameError:
-
     def execfile(fname, globs, locs=None):
         locs = locs or globs
         exec(compile(open(fname).read(), fname, "exec"), globs, locs)
 
-
 version_ns = {}
 execfile(os.path.join(root_dir, 'bonobo/_version.py'), version_ns)
 version = version_ns.get('__version__', 'dev')
 
 setup(
-    name='bonobo',
-    description='Bonobo',
-    license='Apache License, Version 2.0',
-    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1'],
-    version=version,
-    long_description=read('README.rst'),
-    classifiers=read('classifiers.txt', tolines),
-    packages=find_packages(exclude=['ez_setup', 'example', 'test']),
-    include_package_data=True,
-    data_files=[('share/jupyter/nbextensions/bonobo-jupyter', [
-        'bonobo/ext/jupyter/static/extension.js', 'bonobo/ext/jupyter/static/index.js',
-        'bonobo/ext/jupyter/static/index.js.map'
-    ])],
-    extras_require={
-        'dev': [
-            'coverage >=4.2,<4.3', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
-            'pytest-cov >=2.4,<2.5', 'sphinx', 'sphinx_rtd_theme', 'yapf'
-        ],
-        'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']
-    },
-    url='https://bonobo-project.org/',
-    download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version), )
+    name = 'bonobo',
+    description = 'Bonobo',
+    license = 'Apache License, Version 2.0',
+    install_requires = ['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1'],
+    version = version,
+    long_description = read('README.rst'),
+    classifiers = read('classifiers.txt', tolines),
+    packages = find_packages(exclude=['ez_setup', 'example', 'test']),
+    include_package_data = True,
+    data_files = [('share/jupyter/nbextensions/bonobo-jupyter',
+  ['bonobo/ext/jupyter/static/extension.js',
+   'bonobo/ext/jupyter/static/index.js',
+   'bonobo/ext/jupyter/static/index.js.map'])],
+    extras_require = {'dev': ['coverage >=4.2,<4.3',
+         'mock >=2.0,<2.1',
+         'nose >=1.3,<1.4',
+         'pylint >=1.6,<1.7',
+         'pytest >=3,<4',
+         'pytest-cov >=2.4,<2.5',
+         'sphinx',
+         'sphinx_rtd_theme',
+         'yapf'],
+ 'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']},
+    url = 'https://bonobo-project.org/',
+    download_url = 'https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
+)

From 6bfe751c736d753e09a4e7d1eca6e1377c918646 Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Thu, 29 Dec 2016 18:16:41 +0100
Subject: [PATCH 3/6] release: 0.1.3

---
 setup.py | 52 ++++++++++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/setup.py b/setup.py
index f0d6724..a19e5bd 100644
--- a/setup.py
+++ b/setup.py
@@ -8,47 +8,47 @@ root_dir = os.path.dirname(os.path.abspath(__file__))
 
 tolines = lambda c: list(filter(None, map(lambda s: s.strip(), c.split('\n'))))
 
+
 def read(filename, flt=None):
     with open(filename) as f:
         content = f.read().strip()
         return flt(content) if callable(flt) else content
 
+
 # Py3 compatibility hacks, borrowed from IPython.
 try:
     execfile
 except NameError:
+
     def execfile(fname, globs, locs=None):
         locs = locs or globs
         exec(compile(open(fname).read(), fname, "exec"), globs, locs)
 
+
 version_ns = {}
 execfile(os.path.join(root_dir, 'bonobo/_version.py'), version_ns)
 version = version_ns.get('__version__', 'dev')
 
 setup(
-    name = 'bonobo',
-    description = 'Bonobo',
-    license = 'Apache License, Version 2.0',
-    install_requires = ['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1'],
-    version = version,
-    long_description = read('README.rst'),
-    classifiers = read('classifiers.txt', tolines),
-    packages = find_packages(exclude=['ez_setup', 'example', 'test']),
-    include_package_data = True,
-    data_files = [('share/jupyter/nbextensions/bonobo-jupyter',
-  ['bonobo/ext/jupyter/static/extension.js',
-   'bonobo/ext/jupyter/static/index.js',
-   'bonobo/ext/jupyter/static/index.js.map'])],
-    extras_require = {'dev': ['coverage >=4.2,<4.3',
-         'mock >=2.0,<2.1',
-         'nose >=1.3,<1.4',
-         'pylint >=1.6,<1.7',
-         'pytest >=3,<4',
-         'pytest-cov >=2.4,<2.5',
-         'sphinx',
-         'sphinx_rtd_theme',
-         'yapf'],
- 'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']},
-    url = 'https://bonobo-project.org/',
-    download_url = 'https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
-)
+    name='bonobo',
+    description='Bonobo',
+    license='Apache License, Version 2.0',
+    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1'],
+    version=version,
+    long_description=read('README.rst'),
+    classifiers=read('classifiers.txt', tolines),
+    packages=find_packages(exclude=['ez_setup', 'example', 'test']),
+    include_package_data=True,
+    data_files=[('share/jupyter/nbextensions/bonobo-jupyter', [
+        'bonobo/ext/jupyter/static/extension.js', 'bonobo/ext/jupyter/static/index.js',
+        'bonobo/ext/jupyter/static/index.js.map'
+    ])],
+    extras_require={
+        'dev': [
+            'coverage >=4.2,<4.3', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
+            'pytest-cov >=2.4,<2.5', 'sphinx', 'sphinx_rtd_theme', 'yapf'
+        ],
+        'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']
+    },
+    url='https://bonobo-project.org/',
+    download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version), )

From f736e7e7e321ce46ca31597fda67fe8d6a52b166 Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Tue, 3 Jan 2017 22:06:09 +0100
Subject: [PATCH 4/6] Working toward sqlalchemy extension. Better ability to
 extend context. Still needs a lot of cleanup.

---
 .style.yapf                                 |   1 +
 Makefile                                    |   8 +-
 Projectfile                                 |   1 +
 bonobo/__init__.py                          |   3 +-
 bonobo/core/__init__.py                     |   3 +-
 bonobo/core/bags.py                         |  41 +++++--
 bonobo/core/contexts.py                     | 112 +++++++++++++++-----
 bonobo/core/errors.py                       |  18 ++--
 bonobo/core/inputs.py                       |  13 ++-
 bonobo/core/services.py                     |   8 +-
 bonobo/core/strategies/executor.py          |  30 +++++-
 bonobo/ext/console/plugin.py                |  53 +++++----
 bonobo/ext/jupyter/plugin.py                |   8 +-
 bonobo/ext/opendatasoft.py                  |  19 ++--
 bonobo/io/csv.py                            |   3 +-
 bonobo/io/file.py                           |   5 +-
 bonobo/util/__init__.py                     |  93 +++++++++++++---
 bonobo/util/helpers.py                      |  12 +--
 docs/conf.py                                |   8 +-
 examples/opendata_fablabs.py                |  18 ++--
 examples/read_cheap_coffeeshops_in_paris.py |   6 +-
 examples/tutorial_basics_summary.py         |   3 +-
 setup.py                                    |  17 +--
 tests/core/test_bags.py                     |  15 ++-
 tests/core/test_stats.py                    |   3 +-
 tests/ext/test_ods.py                       |  25 ++---
 tests/io/test_file.py                       |   3 +-
 27 files changed, 387 insertions(+), 142 deletions(-)

diff --git a/.style.yapf b/.style.yapf
index c9a88d5..eaa5a7a 100644
--- a/.style.yapf
+++ b/.style.yapf
@@ -1,3 +1,4 @@
 [style]
 based_on_style = pep8
 column_limit = 120
+dedent_closing_brackets = true
diff --git a/Makefile b/Makefile
index a26569b..1db98f5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2016-12-29 17:33:45.585172
+# Updated at 2017-01-03 12:10:41.605435
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
@@ -24,13 +24,13 @@ YAPF_OPTIONS ?= -rip
 # Installs the local project dependencies.
 install: $(VIRTUAL_ENV)
 	if [ -z "$(QUICK)" ]; then \
-	    $(PIP) install -Ur $(PYTHON_REQUIREMENTS_FILE) ; \
+	    $(PIP) install -U pip wheel -r $(PYTHON_REQUIREMENTS_FILE) ; \
 	fi
 
 # Installs the local project dependencies, including development-only libraries.
 install-dev: $(VIRTUAL_ENV)
 	if [ -z "$(QUICK)" ]; then \
-	    $(PIP) install -Ur $(PYTHON_REQUIREMENTS_DEV_FILE) ; \
+	    $(PIP) install -U pip wheel -r $(PYTHON_REQUIREMENTS_DEV_FILE) ; \
 	fi
 
 # Cleans up the local mess.
@@ -41,7 +41,7 @@ clean:
 # Setup the local virtualenv, or use the one provided by the current environment.
 $(VIRTUAL_ENV):
 	virtualenv -p $(PYTHON) $(VIRTUAL_ENV)
-	$(PIP) install -U pip\>=9,\<10 wheel\>=0.29,\<1.0
+	$(PIP) install -U pip wheel
 	ln -fs $(VIRTUAL_ENV)/bin/activate activate-$(PYTHON_BASENAME)
 
 lint: install-dev
diff --git a/Projectfile b/Projectfile
index b4ea177..7b3ad10 100644
--- a/Projectfile
+++ b/Projectfile
@@ -23,6 +23,7 @@ enable_features = {
 install_requires = [
     'blessings >=1.6,<1.7',
     'psutil >=5.0,<5.1',
+    'toolz >=0.8,<0.9',
 ]
 
 extras_require = {
diff --git a/bonobo/__init__.py b/bonobo/__init__.py
index 685e08d..e82abba 100644
--- a/bonobo/__init__.py
+++ b/bonobo/__init__.py
@@ -43,11 +43,12 @@ __all__ = [
     'ThreadPoolExecutorStrategy',
     '__version__',
     'console_run',
-    'head',
     'inject',
     'jupyter_run',
+    'limit',
     'log',
     'noop',
+    'pprint',
     'run',
     'service',
     'tee',
diff --git a/bonobo/core/__init__.py b/bonobo/core/__init__.py
index cca4c91..cc66195 100644
--- a/bonobo/core/__init__.py
+++ b/bonobo/core/__init__.py
@@ -1,6 +1,6 @@
 """ Core required libraries. """
 
-from .bags import Bag
+from .bags import Bag, ErrorBag
 from .graphs import Graph
 from .services import inject, service
 from .strategies.executor import ThreadPoolExecutorStrategy, ProcessPoolExecutorStrategy
@@ -8,6 +8,7 @@ from .strategies.naive import NaiveStrategy
 
 __all__ = [
     'Bag',
+    'ErrorBag',
     'Graph',
     'NaiveStrategy',
     'ProcessPoolExecutorStrategy',
diff --git a/bonobo/core/bags.py b/bonobo/core/bags.py
index c4f7c7b..7f695ee 100644
--- a/bonobo/core/bags.py
+++ b/bonobo/core/bags.py
@@ -2,6 +2,11 @@ import itertools
 
 from bonobo.util.tokens import Token
 
+__all__ = [
+    'Bag',
+    'ErrorBag',
+]
+
 INHERIT_INPUT = Token('InheritInput')
 
 
@@ -18,7 +23,8 @@ class Bag:
             return self._args
         return (
             *self._parent.args,
-            *self._args, )
+            *self._args,
+        )
 
     @property
     def kwargs(self):
@@ -34,7 +40,24 @@ class Bag:
         return self._flags
 
     def apply(self, func_or_iter, *args, **kwargs):
-        return func_or_iter(*args, *self.args, **kwargs, **self.kwargs)
+        if callable(func_or_iter):
+            return func_or_iter(*args, *self.args, **kwargs, **self.kwargs)
+
+        if len(args) == 0 and len(kwargs) == 0:
+            try:
+                iter(func_or_iter)
+
+                def generator():
+                    nonlocal func_or_iter
+                    for x in func_or_iter:
+                        yield x
+
+                return generator()
+            except TypeError as exc:
+                print('nop')
+                raise TypeError('Could not apply bag to {}.'.format(func_or_iter)) from exc
+
+        raise TypeError('Could not apply bag to {}.'.format(func_or_iter))
 
     def extend(self, *args, **kwargs):
         return type(self)(*args, _parent=self, **kwargs)
@@ -48,7 +71,13 @@ class Bag:
 
     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()), )))
+            type(self).__name__, ', '.
+            join(itertools.chain(
+                map(repr, self.args),
+                ('{}={}'.format(k, repr(v)) for k, v in self.kwargs.items()),
+            ))
+        )
+
+
+class ErrorBag(Bag):
+    pass
diff --git a/bonobo/core/contexts.py b/bonobo/core/contexts.py
index 6a4d7f0..8a66863 100644
--- a/bonobo/core/contexts.py
+++ b/bonobo/core/contexts.py
@@ -3,7 +3,7 @@ from functools import partial
 from queue import Empty
 from time import sleep
 
-from bonobo.core.bags import Bag, INHERIT_INPUT
+from bonobo.core.bags import Bag, INHERIT_INPUT, ErrorBag
 from bonobo.core.errors import InactiveReadableError
 from bonobo.core.inputs import Input
 from bonobo.core.stats import WithStatistics
@@ -11,11 +11,31 @@ from bonobo.util.lifecycle import get_initializer, get_finalizer
 from bonobo.util.tokens import BEGIN, END, NEW, RUNNING, TERMINATED, NOT_MODIFIED
 
 
+def get_name(mixed):
+    try:
+        return mixed.__name__
+    except AttributeError:
+        return type(mixed).__name__
+
+
+def create_component_context(component, parent):
+    try:
+        CustomComponentContext = component.Context
+    except AttributeError:
+        return ComponentExecutionContext(component, parent=parent)
+
+    if ComponentExecutionContext in CustomComponentContext.__mro__:
+        bases = (CustomComponentContext, )
+    else:
+        bases = (CustomComponentContext, ComponentExecutionContext)
+
+    return type(get_name(component).title() + 'ExecutionContext', bases, {})(component, parent=parent)
+
+
 class ExecutionContext:
     def __init__(self, graph, plugins=None):
         self.graph = graph
-        self.components = [ComponentExecutionContext(component, self) for component in self.graph.components]
-
+        self.components = [create_component_context(component, parent=self) for component in self.graph.components]
         self.plugins = [PluginExecutionContext(plugin, parent=self) for plugin in plugins or ()]
 
         for i, component_context in enumerate(self):
@@ -23,8 +43,10 @@ class ExecutionContext:
                 component_context.outputs = [self[j].input for j in self.graph.outputs_of(i)]
             except KeyError:
                 continue
+
             component_context.input.on_begin = partial(component_context.send, BEGIN, _control=True)
             component_context.input.on_end = partial(component_context.send, END, _control=True)
+            component_context.input.on_finalize = partial(component_context.finalize)
 
     def __getitem__(self, item):
         return self.components[item]
@@ -63,17 +85,19 @@ class AbstractLoopContext:
     def initialize(self):
         # pylint: disable=broad-except
         try:
-            get_initializer(self.wrapped)(self)
+            initializer = get_initializer(self.wrapped)
         except Exception as exc:
             self.handle_error(exc, traceback.format_exc())
+        else:
+            return initializer(self)
 
     def loop(self):
         """Generic loop. A bit boring. """
         while self.alive:
-            self._loop()
+            self.step()
             sleep(self.PERIOD)
 
-    def _loop(self):
+    def step(self):
         """
         TODO xxx this is a step, not a loop
         """
@@ -83,9 +107,11 @@ class AbstractLoopContext:
         """Generic finalizer. """
         # pylint: disable=broad-except
         try:
-            get_finalizer(self.wrapped)(self)
+            finalizer = get_finalizer(self.wrapped)
         except Exception as exc:
-            self.handle_error(exc, traceback.format_exc())
+            return self.handle_error(exc, traceback.format_exc())
+        else:
+            return finalizer(self)
 
     def handle_error(self, exc, trace):
         """
@@ -112,7 +138,7 @@ class PluginExecutionContext(AbstractLoopContext):
     def shutdown(self):
         self.alive = False
 
-    def _loop(self):
+    def step(self):
         try:
             self.wrapped.run(self)
         except Exception as exc:  # pylint: disable=broad-except
@@ -157,13 +183,17 @@ class ComponentExecutionContext(WithStatistics, AbstractLoopContext):
         return (
             (
                 'in',
-                self.stats['in'], ),
+                self.stats['in'],
+            ),
             (
                 'out',
-                self.stats['out'], ),
+                self.stats['out'],
+            ),
             (
                 'err',
-                self.stats['err'], ), )
+                self.stats['err'],
+            ),
+        )
 
     def recv(self, *messages):
         """
@@ -195,7 +225,7 @@ class ComponentExecutionContext(WithStatistics, AbstractLoopContext):
         self.stats['in'] += 1
         return row
 
-    def _call(self, bag):
+    def apply_on(self, bag):
         # todo add timer
         if getattr(self.component, '_with_context', False):
             return bag.apply(self.component, self)
@@ -203,10 +233,29 @@ class ComponentExecutionContext(WithStatistics, AbstractLoopContext):
 
     def initialize(self):
         # pylint: disable=broad-except
-        assert self.state is NEW, ('A {} can only be run once, and thus is expected to be in {} state at '
-                                   'initialization time.').format(type(self).__name__, NEW)
+        assert self.state is NEW, (
+            'A {} can only be run once, and thus is expected to be in {} state at '
+            'initialization time.'
+        ).format(type(self).__name__, NEW)
         self.state = RUNNING
-        super().initialize()
+
+        try:
+            initializer_outputs = super().initialize()
+            self.handle(None, initializer_outputs)
+        except Exception as exc:
+            self.handle_error(exc, traceback.format_exc())
+
+    def finalize(self):
+        # pylint: disable=broad-except
+        assert self.state is RUNNING, ('A {} must be in {} state at finalization time.'
+                                       ).format(type(self).__name__, RUNNING)
+        self.state = TERMINATED
+
+        try:
+            finalizer_outputs = super().finalize()
+            self.handle(None, finalizer_outputs)
+        except Exception as exc:
+            self.handle_error(exc, traceback.format_exc())
 
     def loop(self):
         while True:
@@ -228,34 +277,39 @@ class ComponentExecutionContext(WithStatistics, AbstractLoopContext):
         output channel."""
 
         input_bag = self.get()
-        outputs = self._call(input_bag)
+        outputs = self.apply_on(input_bag)
+        self.handle(input_bag, outputs)
 
+    def run(self):
+        self.initialize()
+        self.loop()
+
+    def handle(self, input_bag, outputs):
         # self._exec_time += timer.duration
         # Put data onto output channels
         try:
             outputs = _iter(outputs)
-        except TypeError:
+        except TypeError:  # not an iterator
             if outputs:
-                self.send(_resolve(input_bag, outputs))
+                if isinstance(outputs, ErrorBag):
+                    outputs.apply(self.handle_error)
+                else:
+                    self.send(_resolve(input_bag, outputs))
             else:
                 # case with no result, an execution went through anyway, use for stats.
                 # self._exec_count += 1
                 pass
         else:
-            while True:
+            while True:  # iterator
                 try:
                     output = next(outputs)
                 except StopIteration:
                     break
-                self.send(_resolve(input_bag, output))
-
-    def finalize(self):
-        # pylint: disable=broad-except
-        assert self.state is RUNNING, ('A {} must be in {} state at finalization time.').format(
-            type(self).__name__, RUNNING)
-        self.state = TERMINATED
-
-        super().finalize()
+                else:
+                    if isinstance(output, ErrorBag):
+                        output.apply(self.handle_error)
+                    else:
+                        self.send(_resolve(input_bag, output))
 
 
 def _iter(mixed):
diff --git a/bonobo/core/errors.py b/bonobo/core/errors.py
index b82976d..7718de8 100644
--- a/bonobo/core/errors.py
+++ b/bonobo/core/errors.py
@@ -20,9 +20,12 @@ class AbstractError(NotImplementedError):
     """Abstract error is a convenient error to declare a method as "being left as an exercise for the reader"."""
 
     def __init__(self, method):
-        super().__init__('Call to abstract method {class_name}.{method_name}(...): missing implementation.'.format(
-            class_name=method.__self__.__name__,
-            method_name=method.__name__, ))
+        super().__init__(
+            'Call to abstract method {class_name}.{method_name}(...): missing implementation.'.format(
+                class_name=method.__self__.__name__,
+                method_name=method.__name__,
+            )
+        )
 
 
 class InactiveIOError(IOError):
@@ -39,9 +42,12 @@ 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, ))
+        super(ValidationError, self).__init__(
+            'Validation error in {class_name}: {message}'.format(
+                class_name=type(inst).__name__,
+                message=message,
+            )
+        )
 
 
 class ProhibitedOperationError(RuntimeError):
diff --git a/bonobo/core/inputs.py b/bonobo/core/inputs.py
index 1680e18..6598517 100644
--- a/bonobo/core/inputs.py
+++ b/bonobo/core/inputs.py
@@ -48,12 +48,17 @@ class Input(Queue, Readable, Writable):
 
         self._runlevel = 0
         self._writable_runlevel = 0
+        self.on_initialize = noop
         self.on_begin = noop
         self.on_end = noop
+        self.on_finalize = noop
 
     def put(self, data, block=True, timeout=None):
         # Begin token is a metadata to raise the input runlevel.
         if data == BEGIN:
+            if not self._runlevel:
+                self.on_initialize()
+
             self._runlevel += 1
             self._writable_runlevel += 1
 
@@ -78,14 +83,18 @@ class Input(Queue, Readable, Writable):
         data = Queue.get(self, block, timeout)
 
         if data == END:
+            if self._runlevel == 1:
+                self.on_finalize()
+
             self._runlevel -= 1
 
             # callback
             self.on_end()
 
             if not self.alive:
-                raise InactiveReadableError('Cannot get() on an inactive {} (runlevel just reached 0).'.format(
-                    Readable.__name__))
+                raise InactiveReadableError(
+                    'Cannot get() on an inactive {} (runlevel just reached 0).'.format(Readable.__name__)
+                )
             return self.get(block, timeout)
 
         return data
diff --git a/bonobo/core/services.py b/bonobo/core/services.py
index 05d1724..8c53c6b 100644
--- a/bonobo/core/services.py
+++ b/bonobo/core/services.py
@@ -45,9 +45,11 @@ def inject(*iargs, **ikwargs):
     def wrapper(target):
         @functools.wraps(target)
         def wrapped(*args, **kwargs):
-            return target(*itertools.chain(map(resolve, iargs), args),
-                          **{ ** kwargs, ** {k: resolve(v)
-                                             for k, v in ikwargs.items()}})
+            return target(
+                *itertools.chain(map(resolve, iargs), args),
+                **{ ** kwargs, ** {k: resolve(v)
+                                   for k, v in ikwargs.items()}}
+            )
 
         return wrapped
 
diff --git a/bonobo/core/strategies/executor.py b/bonobo/core/strategies/executor.py
index 038522f..804c7e2 100644
--- a/bonobo/core/strategies/executor.py
+++ b/bonobo/core/strategies/executor.py
@@ -2,10 +2,10 @@ import time
 from concurrent.futures import Executor
 from concurrent.futures import ProcessPoolExecutor
 from concurrent.futures import ThreadPoolExecutor
+from threading import Thread
 
 from bonobo.core.strategies.base import Strategy
 from bonobo.util.tokens import BEGIN, END
-
 from ..bags import Bag
 
 
@@ -48,3 +48,31 @@ class ThreadPoolExecutorStrategy(ExecutorStrategy):
 
 class ProcessPoolExecutorStrategy(ExecutorStrategy):
     executor_factory = ProcessPoolExecutor
+
+
+class ThreadCollectionStrategy(Strategy):
+    def execute(self, graph, *args, plugins=None, **kwargs):
+        context = self.create_context(graph, plugins=plugins)
+        context.recv(BEGIN, Bag(), END)
+
+        threads = []
+
+        # for plugin_context in context.plugins:
+        #    threads.append(executor.submit(plugin_context.run))
+
+        for component_context in context.components:
+            thread = Thread(target=component_context.run)
+            threads.append(thread)
+            thread.start()
+
+        # XXX TODO PLUGINS
+        while context.alive and len(threads):
+            time.sleep(0.1)
+            threads = list(filter(lambda thread: thread.is_alive, threads))
+
+        # for plugin_context in context.plugins:
+        #    plugin_context.shutdown()
+
+        # executor.shutdown()
+
+        return context
diff --git a/bonobo/ext/console/plugin.py b/bonobo/ext/console/plugin.py
index e23beb7..699a6c5 100644
--- a/bonobo/ext/console/plugin.py
+++ b/bonobo/ext/console/plugin.py
@@ -53,9 +53,10 @@ class ConsoleOutputPlugin(Plugin):
     def _write(self, context, rewind):
         profile, debug = False, False
         if profile:
-            append = (('Memory', '{0:.2f} Mb'.format(memory_usage())),
-                      # ('Total time', '{0} s'.format(execution_time(harness))),
-                      )
+            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, debug=debug, profile=profile, rewind=rewind)
@@ -77,25 +78,35 @@ class ConsoleOutputPlugin(Plugin):
 
         for i, component in enumerate(context):
             if component.alive:
-                _line = ''.join((
-                    t.black('({})'.format(i + 1)),
-                    ' ',
-                    t.bold(t.white('+')),
-                    ' ',
-                    component.name,
-                    ' ',
-                    component.get_stats_as_string(
-                        debug=debug, profile=profile),
-                    ' ', ))
+                _line = ''.join(
+                    (
+                        t.black('({})'.format(i + 1)),
+                        ' ',
+                        t.bold(t.white('+')),
+                        ' ',
+                        component.name,
+                        ' ',
+                        component.get_stats_as_string(
+                            debug=debug, profile=profile
+                        ),
+                        ' ',
+                    )
+                )
             else:
-                _line = t.black(''.join((
-                    '({})'.format(i + 1),
-                    ' - ',
-                    component.name,
-                    ' ',
-                    component.get_stats_as_string(
-                        debug=debug, profile=profile),
-                    ' ', )))
+                _line = t.black(
+                    ''.join(
+                        (
+                            '({})'.format(i + 1),
+                            ' - ',
+                            component.name,
+                            ' ',
+                            component.get_stats_as_string(
+                                debug=debug, profile=profile
+                            ),
+                            ' ',
+                        )
+                    )
+                )
             print(prefix + _line + t.clear_eol)
 
         if append:
diff --git a/bonobo/ext/jupyter/plugin.py b/bonobo/ext/jupyter/plugin.py
index 63483ce..cb598a3 100644
--- a/bonobo/ext/jupyter/plugin.py
+++ b/bonobo/ext/jupyter/plugin.py
@@ -6,9 +6,11 @@ try:
 except ImportError as e:
     import logging
 
-    logging.exception('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.')
+    logging.exception(
+        '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.'
+    )
 
 
 class JupyterOutputPlugin(Plugin):
diff --git a/bonobo/ext/opendatasoft.py b/bonobo/ext/opendatasoft.py
index 9fb8d61..f996801 100644
--- a/bonobo/ext/opendatasoft.py
+++ b/bonobo/ext/opendatasoft.py
@@ -3,17 +3,20 @@ from urllib.parse import urlencode
 import requests  # todo: make this a service so we can substitute it ?
 
 
-def from_opendatasoft_api(dataset=None,
-                          endpoint='{scheme}://{netloc}{path}',
-                          scheme='https',
-                          netloc='data.opendatasoft.com',
-                          path='/api/records/1.0/search/',
-                          rows=100,
-                          **kwargs):
+def from_opendatasoft_api(
+    dataset=None,
+    endpoint='{scheme}://{netloc}{path}',
+    scheme='https',
+    netloc='data.opendatasoft.com',
+    path='/api/records/1.0/search/',
+    rows=100,
+    **kwargs
+):
     path = path if path.startswith('/') else '/' + path
     params = (
         ('dataset', dataset),
-        ('rows', rows), ) + tuple(sorted(kwargs.items()))
+        ('rows', rows),
+    ) + tuple(sorted(kwargs.items()))
     base_url = endpoint.format(scheme=scheme, netloc=netloc, path=path) + '?' + urlencode(params)
 
     def _extract_ods():
diff --git a/bonobo/io/csv.py b/bonobo/io/csv.py
index aae58d5..72998d2 100644
--- a/bonobo/io/csv.py
+++ b/bonobo/io/csv.py
@@ -59,7 +59,8 @@ class CsvReader(CsvHandler, FileReader):
             if len(row) != field_count:
                 raise ValueError('Got a line with %d fields, expecting %d.' % (
                     len(row),
-                    field_count, ))
+                    field_count,
+                ))
 
             yield dict(zip(headers, row))
 
diff --git a/bonobo/io/file.py b/bonobo/io/file.py
index fa6374e..71be39e 100644
--- a/bonobo/io/file.py
+++ b/bonobo/io/file.py
@@ -36,6 +36,7 @@ class FileHandler:
         :param ctx:
         :return:
         """
+
         assert not hasattr(ctx, 'file'), 'A file pointer is already in the context... I do not know what to say...'
         ctx.file = self.open()
 
@@ -95,8 +96,8 @@ class FileWriter(Writer):
     mode = 'w+'
 
     def initialize(self, ctx):
-        super().initialize(ctx)
         ctx.line = 0
+        return super().initialize(ctx)
 
     def write(self, ctx, row):
         """
@@ -114,4 +115,4 @@ class FileWriter(Writer):
 
     def finalize(self, ctx):
         del ctx.line
-        super().finalize(ctx)
+        return super().finalize(ctx)
diff --git a/bonobo/util/__init__.py b/bonobo/util/__init__.py
index 4a15b40..9da50a9 100644
--- a/bonobo/util/__init__.py
+++ b/bonobo/util/__init__.py
@@ -1,47 +1,116 @@
 """ Various simple utilities. """
 
 import functools
-import pprint
+from pprint import pprint as _pprint
+
+import blessings
 
-from .tokens import NOT_MODIFIED
 from .helpers import run, console_run, jupyter_run
+from .tokens import NOT_MODIFIED
 
 __all__ = [
     'NOT_MODIFIED',
     'console_run',
-    'head',
     'jupyter_run',
+    'limit',
     'log',
     'noop',
+    'pprint',
     'run',
     'tee',
 ]
 
 
-def head(n=10):
+def identity(x):
+    return x
+
+
+def limit(n=10):
     i = 0
 
-    def _head(x):
+    def _limit(*args, **kwargs):
         nonlocal i, n
         i += 1
         if i <= n:
-            yield x
+            yield NOT_MODIFIED
 
-    _head.__name__ = 'head({})'.format(n)
-    return _head
+    _limit.__name__ = 'limit({})'.format(n)
+    return _limit
 
 
 def tee(f):
     @functools.wraps(f)
-    def wrapped(x):
+    def wrapped(*args, **kwargs):
         nonlocal f
-        f(x)
-        return x
+        f(*args, **kwargs)
+        return NOT_MODIFIED
 
     return wrapped
 
 
-log = tee(pprint.pprint)
+log = tee(_pprint)
+
+
+def pprint(title_keys=('title', 'name', 'id'), print_values=True, sort=True):
+    term = blessings.Terminal()
+
+    def _pprint(*args, **kwargs):
+        nonlocal title_keys, term, sort, print_values
+
+        row = args[0]
+        for key in title_keys:
+            if key in row:
+                print(term.bold(row.get(key)))
+                break
+
+        if print_values:
+            for k in sorted(row) if sort else row:
+                print(
+                    '  • {t.blue}{k}{t.normal} : {t.black}({tp}){t.normal} {v}{t.clear_eol}'.format(
+                        k=k, v=repr(row[k]), t=term, tp=type(row[k]).__name__
+                    )
+                )
+
+        yield NOT_MODIFIED
+
+    _pprint.__name__ = 'pprint'
+
+    return _pprint
+
+
+'''
+
+    def writehr(self, label=None):
+        width = t.width or 80
+
+        if label:
+            label = str(label)
+            sys.stderr.write(t.black('·' * 4) + shade('{') + label + shade('}') + t.black('·' * (width - (6+len(label)) - 1)) + '\n')
+        else:
+            sys.stderr.write(t.black('·' * (width-1) + '\n'))
+
+
+    def writeln(self, s):
+        """Output method."""
+        sys.stderr.write(self.format(s) + '\n')
+
+    def initialize(self):
+        self.lineno = 0
+
+    def transform(self, hash, channel=STDIN):
+        """Actual transformation."""
+        self.lineno += 1
+        if not self.condition or self.condition(hash):
+            hash = hash.copy()
+            hash = hash if not isinstance(self.field_filter, collections.Callable) else hash.restrict(self.field_filter)
+            if self.clean:
+                hash = hash.restrict(lambda k: len(k) and k[0] != '_')
+            self.writehr(self.lineno)
+            self.writeln(hash)
+            self.writehr()
+            sys.stderr.write('\n')
+        yield hash
+'''
 
 
 def noop(*args, **kwargs):  # pylint: disable=unused-argument
diff --git a/bonobo/util/helpers.py b/bonobo/util/helpers.py
index 5e3538f..35b6459 100644
--- a/bonobo/util/helpers.py
+++ b/bonobo/util/helpers.py
@@ -1,20 +1,20 @@
-def run(*chain, plugins=None):
+def run(*chain, plugins=None, strategy=None):
     from bonobo import Graph, ThreadPoolExecutorStrategy
 
     graph = Graph()
     graph.add_chain(*chain)
 
-    executor = ThreadPoolExecutorStrategy()
+    executor = (strategy or ThreadPoolExecutorStrategy)()
     return executor.execute(graph, plugins=plugins or [])
 
 
-def console_run(*chain, output=True, plugins=None):
+def console_run(*chain, output=True, plugins=None, strategy=None):
     from bonobo.ext.console import ConsoleOutputPlugin
 
-    return run(*chain, plugins=(plugins or []) + [ConsoleOutputPlugin()] if output else [])
+    return run(*chain, plugins=(plugins or []) + [ConsoleOutputPlugin()] if output else [], strategy=strategy)
 
 
-def jupyter_run(*chain, plugins=None):
+def jupyter_run(*chain, plugins=None, strategy=None):
     from bonobo.ext.jupyter import JupyterOutputPlugin
 
-    return run(*chain, plugins=(plugins or []) + [JupyterOutputPlugin()])
+    return run(*chain, plugins=(plugins or []) + [JupyterOutputPlugin()], strategy=strategy)
diff --git a/docs/conf.py b/docs/conf.py
index 8fb96ed..68e9d7a 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -153,8 +153,12 @@ man_pages = [(master_doc, 'bonobo', 'Bonobo Documentation', [author], 1)]
 # Grouping the document tree into Texinfo files. List of tuples
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
-texinfo_documents = [(master_doc, 'Bonobo', 'Bonobo Documentation', author, 'Bonobo',
-                      'One line description of project.', 'Miscellaneous'), ]
+texinfo_documents = [
+    (
+        master_doc, 'Bonobo', 'Bonobo Documentation', author, 'Bonobo', 'One line description of project.',
+        'Miscellaneous'
+    ),
+]
 
 # -- Options for Epub output ----------------------------------------------
 
diff --git a/examples/opendata_fablabs.py b/examples/opendata_fablabs.py
index b8a87d8..9dc7efa 100644
--- a/examples/opendata_fablabs.py
+++ b/examples/opendata_fablabs.py
@@ -40,10 +40,14 @@ def display(row):
     print(t.bold(row.get('name')))
 
     address = list(
-        filter(None, (
-            ' '.join(filter(None, (row.get('postal_code', None), row.get('city', None)))),
-            row.get('county', None),
-            row.get('country'), )))
+        filter(
+            None, (
+                ' '.join(filter(None, (row.get('postal_code', None), row.get('city', None)))),
+                row.get('county', None),
+                row.get('country'),
+            )
+        )
+    )
 
     print('  - {}: {address}'.format(t.blue('address'), address=', '.join(address)))
     print('  - {}: {links}'.format(t.blue('links'), links=', '.join(row['links'])))
@@ -54,9 +58,11 @@ def display(row):
 if __name__ == '__main__':
     console_run(
         from_opendatasoft_api(
-            API_DATASET, netloc=API_NETLOC, timezone='Europe/Paris'),
+            API_DATASET, netloc=API_NETLOC, timezone='Europe/Paris'
+        ),
         normalize,
         filter_france,
         tee(display),
         JsonWriter('fablabs.json'),
-        output=True, )
+        output=True,
+    )
diff --git a/examples/read_cheap_coffeeshops_in_paris.py b/examples/read_cheap_coffeeshops_in_paris.py
index 8e701e3..5c8f05c 100644
--- a/examples/read_cheap_coffeeshops_in_paris.py
+++ b/examples/read_cheap_coffeeshops_in_paris.py
@@ -8,8 +8,10 @@ OUTPUT_FILENAME = realpath(join(dirname(__file__), 'datasets/cheap_coffeeshops_i
 
 console_run(
     from_opendatasoft_api(
-        'liste-des-cafes-a-un-euro', netloc='opendata.paris.fr'),
+        'liste-des-cafes-a-un-euro', netloc='opendata.paris.fr'
+    ),
     lambda row: '{nom_du_cafe}, {adresse}, {arrondissement} Paris, France'.format(**row),
-    FileWriter(OUTPUT_FILENAME), )
+    FileWriter(OUTPUT_FILENAME),
+)
 
 print('Import done, read {} for results.'.format(OUTPUT_FILENAME))
diff --git a/examples/tutorial_basics_summary.py b/examples/tutorial_basics_summary.py
index 60a5452..74a8f9a 100644
--- a/examples/tutorial_basics_summary.py
+++ b/examples/tutorial_basics_summary.py
@@ -9,7 +9,8 @@ def yield_from(*args):
 graph = Graph(
     lambda: (x for x in ('foo', 'bar', 'baz')),
     str.upper,
-    print, )
+    print,
+)
 
 # Use a thread pool.
 executor = ThreadPoolExecutorStrategy()
diff --git a/setup.py b/setup.py
index a19e5bd..9abfacf 100644
--- a/setup.py
+++ b/setup.py
@@ -33,16 +33,20 @@ setup(
     name='bonobo',
     description='Bonobo',
     license='Apache License, Version 2.0',
-    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1'],
+    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1', 'toolz >=0.8,<0.9'],
     version=version,
     long_description=read('README.rst'),
     classifiers=read('classifiers.txt', tolines),
     packages=find_packages(exclude=['ez_setup', 'example', 'test']),
     include_package_data=True,
-    data_files=[('share/jupyter/nbextensions/bonobo-jupyter', [
-        'bonobo/ext/jupyter/static/extension.js', 'bonobo/ext/jupyter/static/index.js',
-        'bonobo/ext/jupyter/static/index.js.map'
-    ])],
+    data_files=[
+        (
+            'share/jupyter/nbextensions/bonobo-jupyter', [
+                'bonobo/ext/jupyter/static/extension.js', 'bonobo/ext/jupyter/static/index.js',
+                'bonobo/ext/jupyter/static/index.js.map'
+            ]
+        )
+    ],
     extras_require={
         'dev': [
             'coverage >=4.2,<4.3', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
@@ -51,4 +55,5 @@ setup(
         'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']
     },
     url='https://bonobo-project.org/',
-    download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version), )
+    download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
+)
diff --git a/tests/core/test_bags.py b/tests/core/test_bags.py
index 5998381..6c7bb62 100644
--- a/tests/core/test_bags.py
+++ b/tests/core/test_bags.py
@@ -5,7 +5,8 @@ from bonobo.core.bags import INHERIT_INPUT
 
 args = (
     'foo',
-    'bar', )
+    'bar',
+)
 kwargs = dict(acme='corp')
 
 
@@ -40,13 +41,15 @@ def test_inherit():
 
     assert bag2.args == (
         'a',
-        'b', )
+        'b',
+    )
     assert bag2.kwargs == {'a': 1, 'b': 2}
     assert INHERIT_INPUT in bag2.flags
 
     assert bag3.args == (
         'a',
-        'c', )
+        'c',
+    )
     assert bag3.kwargs == {'a': 1, 'c': 3}
     assert bag3.flags is ()
 
@@ -57,7 +60,8 @@ def test_inherit():
     bag4.set_parent(bag)
     assert bag4.args == (
         'a',
-        'd', )
+        'd',
+    )
     assert bag4.kwargs == {'a': 1, 'd': 4}
     assert bag4.flags is ()
 
@@ -65,7 +69,8 @@ def test_inherit():
     assert bag4.args == (
         'a',
         'c',
-        'd', )
+        'd',
+    )
     assert bag4.kwargs == {'a': 1, 'c': 3, 'd': 4}
     assert bag4.flags is ()
 
diff --git a/tests/core/test_stats.py b/tests/core/test_stats.py
index 820d4da..dd0b002 100644
--- a/tests/core/test_stats.py
+++ b/tests/core/test_stats.py
@@ -5,7 +5,8 @@ class MyThingWithStats(WithStatistics):
     def get_stats(self, *args, **kwargs):
         return (
             ('foo', 42),
-            ('bar', 69), )
+            ('bar', 69),
+        )
 
 
 def test_with_statistics():
diff --git a/tests/ext/test_ods.py b/tests/ext/test_ods.py
index eef0db7..79786f2 100644
--- a/tests/ext/test_ods.py
+++ b/tests/ext/test_ods.py
@@ -19,17 +19,18 @@ class ResponseMock:
 def test_read_from_opendatasoft_api():
     extract = from_opendatasoft_api('http://example.com/', 'test-a-set')
     with patch(
-            'requests.get', return_value=ResponseMock([
-                {
-                    'fields': {
-                        'foo': 'bar'
-                    }
-                },
-                {
-                    'fields': {
-                        'foo': 'zab'
-                    }
-                },
-            ])):
+        'requests.get', return_value=ResponseMock([
+            {
+                'fields': {
+                    'foo': 'bar'
+                }
+            },
+            {
+                'fields': {
+                    'foo': 'zab'
+                }
+            },
+        ])
+    ):
         for line in extract():
             assert 'foo' in line
diff --git a/tests/io/test_file.py b/tests/io/test_file.py
index 32566a5..3816233 100644
--- a/tests/io/test_file.py
+++ b/tests/io/test_file.py
@@ -11,7 +11,8 @@ from bonobo.util.tokens import BEGIN, END
     [
         (('ACME', ), 'ACME'),  # one line...
         (('Foo', 'Bar', 'Baz'), 'Foo\nBar\nBaz'),  # more than one line...
-    ])
+    ]
+)
 def test_file_writer_in_context(tmpdir, lines, output):
     file = tmpdir.join('output.txt')
 

From c9b000f65e722a2136f7d7c7bf196092c3fe7b8e Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Sat, 7 Jan 2017 10:37:59 +0100
Subject: [PATCH 5/6] adds requests dependency.

---
 Makefile    |  2 +-
 Projectfile |  2 ++
 setup.py    | 58 ++++++++++++++++++++++++++---------------------------
 3 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/Makefile b/Makefile
index 1db98f5..d8307c5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2017-01-03 12:10:41.605435
+# Updated at 2017-01-07 10:37:43.401814
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
diff --git a/Projectfile b/Projectfile
index 7b3ad10..b4b76e7 100644
--- a/Projectfile
+++ b/Projectfile
@@ -23,7 +23,9 @@ enable_features = {
 install_requires = [
     'blessings >=1.6,<1.7',
     'psutil >=5.0,<5.1',
+    'requests >=2.12,<2.13',
     'toolz >=0.8,<0.9',
+
 ]
 
 extras_require = {
diff --git a/setup.py b/setup.py
index 9abfacf..4f41635 100644
--- a/setup.py
+++ b/setup.py
@@ -8,52 +8,50 @@ root_dir = os.path.dirname(os.path.abspath(__file__))
 
 tolines = lambda c: list(filter(None, map(lambda s: s.strip(), c.split('\n'))))
 
-
 def read(filename, flt=None):
     with open(filename) as f:
         content = f.read().strip()
         return flt(content) if callable(flt) else content
 
-
 # Py3 compatibility hacks, borrowed from IPython.
 try:
     execfile
 except NameError:
-
     def execfile(fname, globs, locs=None):
         locs = locs or globs
         exec(compile(open(fname).read(), fname, "exec"), globs, locs)
 
-
 version_ns = {}
 execfile(os.path.join(root_dir, 'bonobo/_version.py'), version_ns)
 version = version_ns.get('__version__', 'dev')
 
 setup(
-    name='bonobo',
-    description='Bonobo',
-    license='Apache License, Version 2.0',
-    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1', 'toolz >=0.8,<0.9'],
-    version=version,
-    long_description=read('README.rst'),
-    classifiers=read('classifiers.txt', tolines),
-    packages=find_packages(exclude=['ez_setup', 'example', 'test']),
-    include_package_data=True,
-    data_files=[
-        (
-            'share/jupyter/nbextensions/bonobo-jupyter', [
-                'bonobo/ext/jupyter/static/extension.js', 'bonobo/ext/jupyter/static/index.js',
-                'bonobo/ext/jupyter/static/index.js.map'
-            ]
-        )
-    ],
-    extras_require={
-        'dev': [
-            'coverage >=4.2,<4.3', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
-            'pytest-cov >=2.4,<2.5', 'sphinx', 'sphinx_rtd_theme', 'yapf'
-        ],
-        'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']
-    },
-    url='https://bonobo-project.org/',
-    download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
+    name = 'bonobo',
+    description = 'Bonobo',
+    license = 'Apache License, Version 2.0',
+    install_requires = ['blessings >=1.6,<1.7',
+ 'psutil >=5.0,<5.1',
+ 'requests >=2.12,<2.13',
+ 'toolz >=0.8,<0.9'],
+    version = version,
+    long_description = read('README.rst'),
+    classifiers = read('classifiers.txt', tolines),
+    packages = find_packages(exclude=['ez_setup', 'example', 'test']),
+    include_package_data = True,
+    data_files = [('share/jupyter/nbextensions/bonobo-jupyter',
+  ['bonobo/ext/jupyter/static/extension.js',
+   'bonobo/ext/jupyter/static/index.js',
+   'bonobo/ext/jupyter/static/index.js.map'])],
+    extras_require = {'dev': ['coverage >=4.2,<4.3',
+         'mock >=2.0,<2.1',
+         'nose >=1.3,<1.4',
+         'pylint >=1.6,<1.7',
+         'pytest >=3,<4',
+         'pytest-cov >=2.4,<2.5',
+         'sphinx',
+         'sphinx_rtd_theme',
+         'yapf'],
+ 'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']},
+    url = 'https://bonobo-project.org/',
+    download_url = 'https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
 )

From 9daefd72071efc9396b6b554a849448fe29700c3 Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Tue, 10 Jan 2017 23:09:40 +0100
Subject: [PATCH 6/6] Implements commands as extensions using stevedore; adds
 run and init command.

---
 Makefile                     |  2 +-
 Projectfile                  | 15 ++++++++++++++-
 bonobo/__main__.py           |  4 ++++
 bonobo/commands/__init__.py  | 22 ++++++++++++++++++++++
 bonobo/commands/init.py      | 18 ++++++++++++++++++
 bonobo/commands/run.py       | 29 +++++++++++++++++++++++++++++
 bonobo/util/helpers.py       |  9 +++++++--
 examples/opendata_fablabs.py | 23 ++++++++++++-----------
 setup.py                     | 10 ++++++++--
 9 files changed, 115 insertions(+), 17 deletions(-)
 create mode 100644 bonobo/__main__.py
 create mode 100644 bonobo/commands/__init__.py
 create mode 100644 bonobo/commands/init.py
 create mode 100644 bonobo/commands/run.py

diff --git a/Makefile b/Makefile
index 1db98f5..16e06c2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # This file has been auto-generated.
 # All changes will be lost, see Projectfile.
 #
-# Updated at 2017-01-03 12:10:41.605435
+# Updated at 2017-01-10 23:12:36.230185
 
 PYTHON ?= $(shell which python)
 PYTHON_BASENAME ?= $(shell basename $(PYTHON))
diff --git a/Projectfile b/Projectfile
index 7b3ad10..2bc6dc7 100644
--- a/Projectfile
+++ b/Projectfile
@@ -23,6 +23,7 @@ enable_features = {
 install_requires = [
     'blessings >=1.6,<1.7',
     'psutil >=5.0,<5.1',
+    'stevedore >=1.19,<1.20',
     'toolz >=0.8,<0.9',
 ]
 
@@ -32,7 +33,7 @@ extras_require = {
         'ipywidgets >=6.0.0.beta5'
     ],
     'dev': [
-        'coverage >=4.2,<4.3',
+        'coverage >=4.3,<4.4',
         'mock >=2.0,<2.1',
         'nose >=1.3,<1.4',
         'pylint >=1.6,<1.7',
@@ -52,6 +53,18 @@ data_files = [
     ]),
 ]
 
+entry_points = {
+    'console_scripts': [
+        'bonobo = bonobo.commands:entrypoint'
+    ],
+    'bonobo.commands': [
+        'init = bonobo.commands.init:register',
+        'run = bonobo.commands.run:register',
+    ],
+    'edgy.project.features': [
+        'bonobo = bonobo.ext.edgy.project.feature:BonoboFeature'
+    ]
+}
 
 @listen('edgy.project.feature.make.on_generate', priority=10)
 def on_make_generate_docker_targets(event):
diff --git a/bonobo/__main__.py b/bonobo/__main__.py
new file mode 100644
index 0000000..05ed120
--- /dev/null
+++ b/bonobo/__main__.py
@@ -0,0 +1,4 @@
+from bonobo.commands import entrypoint
+
+if __name__ == '__main__':
+    entrypoint()
diff --git a/bonobo/commands/__init__.py b/bonobo/commands/__init__.py
new file mode 100644
index 0000000..bc61ebf
--- /dev/null
+++ b/bonobo/commands/__init__.py
@@ -0,0 +1,22 @@
+import argparse
+
+from stevedore import ExtensionManager
+
+
+def entrypoint():
+    parser = argparse.ArgumentParser()
+
+    subparsers = parser.add_subparsers(dest='command')
+    subparsers.required = True
+
+    def register_extension(ext):
+        parser = subparsers.add_parser(ext.name)
+        command = ext.plugin(parser)
+        parser.set_defaults(command=command)
+
+    mgr = ExtensionManager(namespace='bonobo.commands', )
+    mgr.map(register_extension)
+
+    args = parser.parse_args().__dict__
+    command = args.pop('command')
+    command(**args)
diff --git a/bonobo/commands/init.py b/bonobo/commands/init.py
new file mode 100644
index 0000000..a1ab700
--- /dev/null
+++ b/bonobo/commands/init.py
@@ -0,0 +1,18 @@
+import os
+
+
+def execute():
+    try:
+        import edgy.project
+    except ImportError as exc:
+        raise ImportError(
+            'You must install "edgy.project" to use this command.\n\n $ pip install edgy.project\n'
+        ) from exc
+
+    from edgy.project.__main__ import handle_init
+
+    return handle_init(os.path.join(os.getcwd(), 'Projectfile'))
+
+
+def register(parser):
+    return execute
diff --git a/bonobo/commands/run.py b/bonobo/commands/run.py
new file mode 100644
index 0000000..c0f9e14
--- /dev/null
+++ b/bonobo/commands/run.py
@@ -0,0 +1,29 @@
+import argparse
+
+from bonobo import Graph, console_run
+
+
+def execute(file):
+    with file:
+        code = compile(file.read(), file.name, 'exec')
+
+    context = {}
+
+    try:
+        exec(code, context)
+    except Exception as exc:
+        raise
+
+    graphs = dict((k, v) for k, v in context.items() if isinstance(v, Graph))
+
+    assert len(graphs) == 1, 'Having more than one graph definition in one file is unsupported for now, but it is ' \
+                             'something that will be implemented in the future. '
+
+    name, graph = list(graphs.items())[0]
+
+    return console_run(graph)
+
+
+def register(parser):
+    parser.add_argument('file', type=argparse.FileType())
+    return execute
diff --git a/bonobo/util/helpers.py b/bonobo/util/helpers.py
index 35b6459..106b04e 100644
--- a/bonobo/util/helpers.py
+++ b/bonobo/util/helpers.py
@@ -1,8 +1,13 @@
 def run(*chain, plugins=None, strategy=None):
     from bonobo import Graph, ThreadPoolExecutorStrategy
 
-    graph = Graph()
-    graph.add_chain(*chain)
+    if len(chain) == 1 and isinstance(chain[0], Graph):
+        graph = chain[0]
+    elif len(chain) >= 1:
+        graph = Graph()
+        graph.add_chain(*chain)
+    else:
+        raise RuntimeError('Empty chain.')
 
     executor = (strategy or ThreadPoolExecutorStrategy)()
     return executor.execute(graph, plugins=plugins or [])
diff --git a/examples/opendata_fablabs.py b/examples/opendata_fablabs.py
index 9dc7efa..6a5f082 100644
--- a/examples/opendata_fablabs.py
+++ b/examples/opendata_fablabs.py
@@ -2,7 +2,7 @@ import json
 
 from blessings import Terminal
 
-from bonobo import console_run, tee, JsonWriter
+from bonobo import console_run, tee, JsonWriter, Graph
 from bonobo.ext.opendatasoft import from_opendatasoft_api
 
 try:
@@ -55,14 +55,15 @@ def display(row):
     print('  - {}: {source}'.format(t.blue('source'), source='datanova/' + API_DATASET))
 
 
+graph = Graph(
+    from_opendatasoft_api(
+        API_DATASET, netloc=API_NETLOC, timezone='Europe/Paris'
+    ),
+    normalize,
+    filter_france,
+    tee(display),
+    JsonWriter('fablabs.json'),
+)
+
 if __name__ == '__main__':
-    console_run(
-        from_opendatasoft_api(
-            API_DATASET, netloc=API_NETLOC, timezone='Europe/Paris'
-        ),
-        normalize,
-        filter_france,
-        tee(display),
-        JsonWriter('fablabs.json'),
-        output=True,
-    )
+    console_run(graph, output=True)
diff --git a/setup.py b/setup.py
index 9abfacf..7e6858d 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,7 @@ setup(
     name='bonobo',
     description='Bonobo',
     license='Apache License, Version 2.0',
-    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1', 'toolz >=0.8,<0.9'],
+    install_requires=['blessings >=1.6,<1.7', 'psutil >=5.0,<5.1', 'stevedore >=1.19,<1.20', 'toolz >=0.8,<0.9'],
     version=version,
     long_description=read('README.rst'),
     classifiers=read('classifiers.txt', tolines),
@@ -49,11 +49,17 @@ setup(
     ],
     extras_require={
         'dev': [
-            'coverage >=4.2,<4.3', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
+            'coverage >=4.3,<4.4', 'mock >=2.0,<2.1', 'nose >=1.3,<1.4', 'pylint >=1.6,<1.7', 'pytest >=3,<4',
             'pytest-cov >=2.4,<2.5', 'sphinx', 'sphinx_rtd_theme', 'yapf'
         ],
         'jupyter': ['jupyter >=1.0,<1.1', 'ipywidgets >=6.0.0.beta5']
     },
+    entry_points={
+        'bonobo.commands': ['init = bonobo.commands.init:register', 'run = bonobo.commands.run:register'],
+        'console_scripts': ['bonobo = bonobo.commands:entrypoint'],
+        'edgy.project.features': ['bonobo = '
+                                  'bonobo.ext.edgy.project.feature:BonoboFeature']
+    },
     url='https://bonobo-project.org/',
     download_url='https://github.com/python-bonobo/bonobo/tarball/{version}'.format(version=version),
 )