| 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 |
| ------- |
| |
| 0.5.3 - 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 |
