JonesComplexity

Flake8 extension to calculate per-line complexity and total code density.

Installation

$ pip install jones-complexity

Usage (Standalone)

$ python -m jones_complexity --max-line-complexity 5 your_file.py

Usage (flake8)

$ flake8 --max-line-complexity 15 --max-jones-score 8 yourproject

We do not make any assumptions on the required configuration, so if no explicit configuration is provided, this plugin will be silent. Enable it by setting --max-jones-score or --max-line-complexity options.

What is this?

Because

if user.get_full_name().toUpper().split(' ')[0] == 'ALICE':
    return True

is harder to read and maintain than

if first_name == 'Alice':
    return True

Shamelessly named after myself, in the tradition of McCabe and Halstead.

Options

We support two options:

--max-line-complexity which sets the maximum complexity for a single line
--max-jones-score which sets maximum median complexity inside a module

You can provide options via:

a command line, this works for both standalone and flake8 usages
if using flake8, setup.cfg and .flake8 files are supported, see docs

Examples

Itself:

$ python -m jones_complexity jones_complexity.py
[
    "jones_complexity.py:46:1: J901 Line 46 is too complex (13)",
    "jones_complexity.py:40:1: J901 Line 40 is too complex (12)",
    ...
    "jones_complexity.py:154:1: J901 Line 154 is too complex (2)",
    "jones_complexity.py:170:1: J901 Line 170 is too complex (2)"
]
Jones Score: 3

PyEsprima:

$ python -m jones_complexity pyesprima.py
Line counts:
[
    "pyesprima.py:4191:1: J901 Line 4191 is too complex (265)",
    "pyesprima.py:41:1: J901 Line 41 is too complex (189)",
    "pyesprima.py:4195:1: J901 Line 4195 is too complex (189)",
    "pyesprima.py:4189:1: J901 Line 4189 is too complex (164)",
    ...
    "pyesprima.py:4963:1: J901 Line 4963 is too complex (2)",
    "pyesprima.py:4978:1: J901 Line 4978 is too complex (2)",
    "pyesprima.py:4996:1: J901 Line 4996 is too complex (2)"
]
Jones Score: 9.0

Miserlou / JonesComplexity