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|
McCabe complexity checker
=========================
Ned's script to check McCabe complexity.
This module provides a plugin for ``flake8``, the Python code checker.
Installation
------------
You can install, upgrade, uninstall ``mccabe`` with these commands::
$ pip install mccabe
$ pip install --upgrade mccabe
$ pip uninstall mccabe
Standalone script
-----------------
The complexity checker can be used directly::
$ python -m mccabe --min 5 mccabe.py
("185:1: 'PathGraphingAstVisitor.visitIf'", 5)
("71:1: 'PathGraph.to_dot'", 5)
("245:1: 'McCabeChecker.run'", 5)
("283:1: 'main'", 7)
("203:1: 'PathGraphingAstVisitor.visitTryExcept'", 5)
("257:1: 'get_code_complexity'", 5)
Plugin for Flake8
-----------------
When both ``flake8 2.0`` and ``mccabe`` are installed, the plugin is
available in ``flake8``::
$ flake8 --version
2.0 (pep8: 1.4.2, pyflakes: 0.6.1, mccabe: 0.2)
By default the plugin is disabled. Use the ``--max-complexity`` switch to
enable it. It will emit a warning if the McCabe complexity of a function is
higher that the value::
$ flake8 --max-complexity 10 coolproject
...
coolproject/mod.py:1204:1: C901 'CoolFactory.prepare' is too complex (14)
This feature is quite useful to detect over-complex code. According to McCabe,
anything that goes beyond 10 is too complex.
Links
-----
* Feedback and ideas: http://mail.python.org/mailman/listinfo/code-quality
* Cyclomatic complexity: http://en.wikipedia.org/wiki/Cyclomatic_complexity.
* Ned Batchelder's script:
http://nedbatchelder.com/blog/200803/python_code_complexity_microtool.html
Changes
-------
0.6.1 - 2017-01-26
``````````````````
* Fix signature for ``PathGraphingAstVisitor.default`` to match the signature
for ``ASTVisitor``
0.6.0 - 2017-01-23
``````````````````
* Add support for Python 3.6
* Fix handling for missing statement types
0.5.3 - 2016-12-14
``````````````````
* Report actual column number of violation instead of the start of the line
0.5.2 - 2016-07-31
``````````````````
* When opening files ourselves, make sure we always name the file variable
0.5.1 - 2016-07-28
``````````````````
* Set default maximum complexity to -1 on the class itself
0.5.0 - 2016-05-30
``````````````````
* PyCon 2016 PDX release
* Add support for Flake8 3.0
0.4.0 - 2016-01-27
``````````````````
* Stop testing on Python 3.2
* Add support for async/await keywords on Python 3.5 from PEP 0492
0.3.1 - 2015-06-14
``````````````````
* Include ``test_mccabe.py`` in releases.
* Always coerce the ``max_complexity`` value from Flake8's entry-point to an
integer.
0.3 - 2014-12-17
````````````````
* Computation was wrong: the mccabe complexity starts at 1, not 2.
* The ``max-complexity`` value is now inclusive. E.g.: if the
value is 10 and the reported complexity is 10, then it passes.
* Add tests.
0.2.1 - 2013-04-03
``````````````````
* Do not require ``setuptools`` in setup.py. It works around an issue
with ``pip`` and Python 3.
0.2 - 2013-02-22
````````````````
* Rename project to ``mccabe``.
* Provide ``flake8.extension`` setuptools entry point.
* Read ``max-complexity`` from the configuration file.
* Rename argument ``min_complexity`` to ``threshold``.
0.1 - 2013-02-11
````````````````
* First release
|
