pylava 0.3.0
Pylava -- Code audit tool for Python
License: MIT
Keywords: pylint,pep8,pycodestyle,pyflakes,mccabe,linter,qa,pep257,pydocstyle

Pylava
======

Pylava is a community maintained fork of `Pylama
<https://github.com/klen/pylama>`_.

.. image:: https://travis-ci.com/pylava/pylava.svg?branch=master
    :target: https://travis-ci.com/pylava/pylava
    :alt: Build Status

.. image:: https://coveralls.io/repos/github/pylava/pylava/badge.svg?branch=master
    :target: https://coveralls.io/github/pylava/pylava?branch=master
    :alt: Coveralls

.. image:: https://img.shields.io/pypi/v/pylava.svg
    :target: https://pypi.org/project/pylava/
    :alt: Version

.. image:: https://readthedocs.org/projects/pylavadocs/badge/?version=latest
    :target: https://pylavadocs.readthedocs.io/en/latest/?badge=latest
    :alt: Documentation Status

Pylava is a code audit tool for Python and JavaScript. Pylava wraps
these tools:

* pycodestyle_ (formerly pep8) © 2012-2013, Florent Xicluna;
* pydocstyle_ (formerly pep257 by Vladimir Keleshev) © 2014, Amir Rachum;
* PyFlakes_ © 2005-2013, Kevin Watters;
* Mccabe_ © Ned Batchelder;
* Pylint_ © 2013, Logilab (should be installed 'pylama_pylint' module);
* Radon_ © Michele Lacchia
* gjslint_ © The Closure Linter Authors (should be installed 'pylama_gjslint' module);

.. _pycodestyle: https://github.com/PyCQA/pycodestyle
.. _pydocstyle: https://github.com/PyCQA/pydocstyle/
.. _PyFlakes: https://github.com/pyflakes/pyflakes
.. _Mccabe: http://nedbatchelder.com/blog/200803/python_code_complexity_microtool.html
.. _Pylint: http://pylint.org
.. _Radon: https://github.com/rubik/radon
.. _gjslint: https://developers.google.com/closure/utilities


.. contents::


Credits
-------

Thanks to:

- `Kirill Klenov <https://github.com/klen>`_ for creating and
  maintaining the original Pylama project. This fork named Pylava is a
  derivative work based on Kirill Klenov's Pylama project.
- Contributors to Pylama.
- Contributors to Pylava.


New in Pylava
-------------

This fork of Pylama differs from the original Pylama project in the
following areas:

- Pylama does not work with Python 3.7 due to `Pylama issue #123
  <https://github.com/klen/pylama/issues/123>`_. While there is a pull
  request to resolve the issue, they are not being merged into the
  project due to lack of maintenance. This fork named Pylava is meant
  for merging useful pull requests into the project, so that the project
  can satsify the current needs of Python developers. This is the
  primary reason why this fork was created.

- The licensing terms of Pylama are unclear. The README of the original
  Pylama project mentioned:

    Licensed under a `BSD license`_.

  It is unclear which BSD license (BSD-3-Clause or BSD-2-Clause) is
  meant here. Moreover there are references to the GNU Lesser General
  Public License (GNU LGPL) also in the project. See `Pylama issue #64
  <https://github.com/klen/pylama/issues/64>`_ for more about this.

  This fork interprets the license section of the README to mean that
  the Pylama project is available under a BSD license in addition to
  certain files being available under GNU LGPL due to the mentions of
  GNU LGPL in such files.

  Further, this fork named Pylava (a derivative work based on Pylama) is
  distributed under the terms of the MIT license which is allowed by BSD
  licenses.

- While the original Pylama project uses the ``develop`` branch as the
  active development branch, this fork uses the ``master`` branch as the
  active development branch.

.. _BSD license: http://www.linfo.org/bsdlicense.html


Documentation
-------------

Documentation is available at https://pylavadocs.readthedocs.io/. Pull
requests with documentation enhancements and/or fixes are awesome and
most welcome.


Requirements
------------

- Python (2.7, 3.5, 3.6, 3.7, 3.8, or 3.9)
- To use JavaScript checker (``gjslint``) you need to install
  ``python-gflags`` with ``pip install python-gflags``.
- If your tests are failing on Win platform you are missing:
  ``curses`` - http://www.lfd.uci.edu/~gohlke/pythonlibs/
  (The curses library supplies a terminal-independent screen-painting
  and keyboard-handling facility for text-based terminals)


Installation
------------

Enter the following command to install Pylava. ::

    $ pip install pylava

With Python 3, you may need to enter the following command instead. ::

    $ pip3 install pylava


Quick Start
-----------

Pylava is easy to use and really fun for checking code quality. Just run
`pylava` and get common output from all pylava plugins (pycodestyle_,
PyFlakes_ and etc)

Recursively check the current directory. ::

    $ pylava

Recursively check a path. ::

    $ pylava <path_to_directory_or_file>

Ignore errors ::

    $ pylava -i W,E501

Note: You could choose a group of errors ``D``, ``E1``, etc., or special
errors ``C0312``.

Choose code checkers ::

    $ pylava -l "pycodestyle,mccabe"

Choose code checkers for JavaScript::

    $ pylava --linters=gjslint --ignore=E:0010 <path_to_directory_or_file>

.. _options:


Set Pylava (checkers) options
-----------------------------

Command line options
~~~~~~~~~~~~~~~~~~~~

::

    $ pylava --help

    usage: pylava [-h] [--verbose] [--version] [--format {pycodestyle,pylint}]
                  [--select SELECT] [--sort SORT] [--linters LINTERS]
                  [--ignore IGNORE] [--skip SKIP] [--report REPORT] [--hook]
                  [--async] [--options OPTIONS] [--force] [--abspath]
                  [paths [paths ...]]

    Code audit tool for python.

    positional arguments:
      paths                 Paths to files or directories for code check.

    optional arguments:
      -h, --help            show this help message and exit
      --verbose, -v         Verbose mode.
      --version             show program's version number and exit
      --format {pycodestyle,pylint}, -f {pycodestyle,pylint}
                            Choose errors format (pycodestyle, pylint).
      --select SELECT, -s SELECT
                            Select errors and warnings. (comma-separated list)
      --sort SORT           Sort result by error types. Ex. E,W,D
      --linters LINTERS, -l LINTERS
                            Select linters. (comma-separated). Choices are
                            mccabe,pycodestyle,pyflakes,pydocstyle.
      --ignore IGNORE, -i IGNORE
                            Ignore errors and warnings. (comma-separated)
      --skip SKIP           Skip files by masks (comma-separated, Ex.
                            */messages.py)
      --report REPORT, -r REPORT
                            Send report to file [REPORT]
      --hook                Install Git (Mercurial) hook.
      --async               Enable async mode. Useful for checking a lot of
                            files. Not supported by pylint.
      --options FILE, -o FILE
                            Specify configuration file. Looks for pylava.ini,
                            setup.cfg, tox.ini, or pytest.ini in the current
                            directory.
      --force, -F           Force code checking (if linter doesnt allow)
      --abspath, -a         Use absolute paths in output.


File modelines
~~~~~~~~~~~~~~

You can set options for Pylava inside a source file. Use
pylava *modeline* for this.

Format: ::

    # pylava:{name1}={value1}:{name2}={value2}:...

Example: ::

     .. Somethere in code
     # pylava:ignore=W:select=W301

Disable code checking for current file: ::

     .. Somethere in code
     # pylava:skip=1

Those options have a higher priority.


Skip lines (noqa)
~~~~~~~~~~~~~~~~~

Just add `# noqa` in end of line to ignore.

Example:

.. code:: python

    def urgent_fuction():
        unused_var = 'No errors here' # noqa


Configuration file
~~~~~~~~~~~~~~~~~~

Pylava looks for a configuration file in the current directory.

The program searches for the first matching ini-style configuration file in
the directories of command line argument. Pylava looks for the configuration
in this order: ::

    pylava.ini
    setup.cfg
    tox.ini
    pytest.ini

The ``--option`` / ``-o`` argument can be used to specify a
configuration file.

Pylava searches for sections whose names start with `pylava`.

The `pylava` section configures global options like `linters` and `skip`.

Example: ::

    [pylava]
    format = pylint
    skip = */.tox/*,*/.env/*
    linters = pylint,mccabe
    ignore = F0401,C0111,E731


Set Code-checkers' options
~~~~~~~~~~~~~~~~~~~~~~~~~~

You could set options for special code checker with pylava configurations.

Example: ::

    [pylava:pyflakes]
    builtins = _

    [pylava:pycodestyle]
    max_line_length = 100

    [pylava:pylint]
    max_line_length = 100
    disable = R

See code-checkers' documentation for more info.


Set options for file (group of files)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You could set options for special file (group of files)
with sections:

The options have a higher priority than in the `pylava` section.

Example: ::

    [pylava:*/pylava/main.py]
    ignore = C901,R0914,W0212
    select = R

    [pylava:*/tests.py]
    ignore = C0110

    [pylava:*/setup.py]
    skip = 1


Pytest integration
------------------

Pylava has Pytest_ support. The package automatically registers itself
as a pytest plugin during installation. Pylava also supports
`pytest_cache` plugin.

Check files with pylava: ::

    pytest --pylava ...

Recommended way to set pylava options when using pytest — configuration
files (see below).

.. _Pytest: http://pytest.org


Writing a linter
----------------

You can write a custom extension for Pylava. Custom linter should be a
python module. Name should be like ``pylava_<name>``.

In ``setup.py``, ``pylava.linter`` entry point should be defined.

Example:

.. code:: python

    setup(
        # ...
        entry_points={
            'pylava.linter': ['lintername = pylava_lintername.main:Linter'],
        }
        # ...
    )

``Linter`` should be instance of ``pylava.lint.Linter`` class. Must
implement two methods:

- ``allow`` takes a path and returns true if linter can check this file for errors.
- ``run`` takes a path and meta keywords params and returns a list of errors.


Example
~~~~~~~

Just a virtual 'WOW' checker.

setup.py:

.. code:: python

    setup(
        name='pylava_wow',
        install_requires=[ 'setuptools' ],
        entry_points={
            'pylava.linter': ['wow = pylava_wow.main:Linter'],
        }
        # ...
    )

pylava_wow.py:

.. code:: python

    from pylava.lint import Linter as BaseLinter

    class Linter(BaseLinter):

        def allow(self, path):
            return 'wow' in path

        def run(self, path, **meta):
            with open(path) as f:
                if 'wow' in f.read():
                    return [{
                        lnum: 0,
                        col: 0,
                        text: 'Wow has been found.',
                        type: 'WOW'
                    }]


Run pylava from python code
---------------------------

.. code:: python

    from pylava.main import check_path, parse_options

    # Use and/or modify 0 or more of the options defined as keys in the
    # variable my_redefined_options below. To use defaults for any
    # option, remove that key completely.
    my_redefined_options = {
        'linters': ['pep257', 'pydocstyle', 'pycodestyle', 'pyflakes' ...],
        'ignore': ['D203', 'D213', 'D406', 'D407', 'D413' ...],
        'select': ['R1705' ...],
        'sort': 'F,E,W,C,D,...',
        'skip': '*__init__.py,*/test/*.py,...',
        'async': True,
        'force': True
        ...
    }
    # relative path of the directory in which pylama should check
    my_path = '...'

    options = parse_options([my_path], **my_redefined_options)
    errors = check_path(options, rootdir='.')


Support
-------

To report bugs, suggest improvements, or ask questions, please create a
new issue at http://github.com/pylava/pylava/issues.


Contributing
------------

Development of Pylava happens at the ``master`` branch of
https://github.com/pylava/pylava.


Contributors
------------

See AUTHORS_.

.. _AUTHORS: https://github.com/pylava/pylava/blob/master/AUTHORS.rst


License
-------

This is free software. You are permitted to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of it, under the
terms of the MIT License. See LICENSE.rst_ for the complete license.

This software is provided WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
LICENSE.rst_ for the complete disclaimer.

.. _LICENSE.rst: https://github.com/pylava/pylava/blob/master/LICENSE.rst

The original README from Pylama that made Pylama available under a BSD
license and the original LICENSE file with the GNU LGPL license text are
archived in the `pylama-archive
<https://github.com/pylava/pylava/tree/master/pylama-archive>`_
directory.