[TIP] pytest-pep8 0.6: configurable PEP8 checking in py.test runs

[holger krekel]

just released an initial version 0.6 of the pytest-pep8 plugin, 
integrating the ``pep8`` module into py.test runs, allowing full
per-project customization and configuration. 

See http://pypi.python.org/pypi/pytest-pep8 for installation
and configuration instructions.

best,
holger

Usage
-----------------

install pytest-pep8 via::

    easy_install pytest-pep8 # or
    pip install pytest-pep8

and then type::

    py.test --pep8
    
to activate source code checking. Every file ending in ``.py`` will be
discovered and checked, starting from the command line arguments.
For example, if you have a file like this::

    # content of myfile.py
 
    somefunc( 123,456)

you can run it with::

    $ py.test --pep8
    =========================== test session starts ============================
    platform linux2 -- Python 2.6.5 -- pytest-2.0.1.dev1
    pep8 ignore opts: E202 E221 E222 E241 E301 E302 E401 E501 E701 W293 W391 W601 W602
    collecting ... collected 1 items
    
    myfile.py F
    
    ================================= FAILURES =================================
    ________________________________ PEP8-check ________________________________
    /tmp/doc-exec-12/myfile.py:2:10: E201 whitespace after '('
    somefunc( 123,456)
             ^
    /tmp/doc-exec-12/myfile.py:2:14: E231 missing whitespace after ','
    somefunc( 123,456)
                 ^
    
    ========================= 1 failed in 0.01 seconds =========================

Note that in the testing header you see the current list of default "ignores".
For the meaning of these error and warning codes, see the error output
when running against your files or checkout `pep8.py
<https://github.com/jcrocholl/pep8/blob/master/pep8.py>`_.

Configuring PEP8 options per-project
---------------------------------------------

Lastly, you may configure PEP8-checking options for your project
by adding an ``pep8options`` entry to your ``pytest.ini``
or ``setup.cfg`` file like this::

    [pytest]
    pep8options = +W293 -E200


Running PEP8 checks and no other tests
---------------------------------------------

You can also restrict your test run to only perform "pep8" tests
and not any other tests by typing::

    py.test --pep8 -k pep8

This will only run tests that are marked with the "pep8" keyword
which is added for the pep8 test items added by this plugin.

Notes
-------------

The repository of this plugin is at http://bitbucket.org/hpk42/pytest-pep8

For more info on py.test see http://pytest.org

The code is partially based on Ronny Pfannschmidt's pytest-codecheckers plugin.