flint 0.2 (experimental)

the modular Python source code checker

Features

• Based on the pep8 and the pyflakes checkers.
• Easy to configure, with unified output.
• Extendable through flint.extension entry points.
• Plugin examples: flint-mccabe and pep8-naming

Installation

You can install, upgrade, uninstall flint with these commands:

$ pip install flint
$ pip install --upgrade flint
$ pip uninstall flint

Usage and output

Flint runs all the registered checkers with a single flint script. It accepts the same options as the pep8 tool and additional options for the plugins. The output merges the errors from all the tools.

Example (with McCabe plugin):

$ flint --version
0.1 (pep8: 1.4.2, pyflakes: 0.6.1, mccabe: 0.1)
$
$ flint --first --max-complexity 10 optparse.py
optparse.py:61:11: E401 multiple imports on one line
optparse.py:65:1: E302 expected 2 blank lines, found 1
optparse.py:235:34: W602 deprecated form of raising exception
optparse.py:265:5: E303 too many blank lines (2)
optparse.py:375:31: E211 whitespace before '('
optparse.py:404:17: E201 whitespace after '{'
optparse.py:404:23: E203 whitespace before ':'
optparse.py:407:53: E202 whitespace before '}'
optparse.py:530:20: E124 closing bracket does not match visual indentation
optparse.py:597:21: W601 .has_key() is deprecated, use 'in'
optparse.py:637:34: E721 do not compare types, use 'isinstance()'
optparse.py:639:80: E501 line too long (81 > 79 characters)
optparse.py:700:17: E125 continuation line does not distinguish itself from next logical line
optparse.py:1387:1: F841 local variable 'stop' is assigned to but never used
optparse.py:1504:1: C901 'OptionParser._process_short_opts' is too complex (10)
$

Configuration

The behaviour may be configured at two levels.

The user settings are read from the ~/.config/flint file. Example:

[flint]
ignore = E226,E302,E41
max-line-length = 160

At the project level, a tox.ini file or a setup.cfg file is read if present. Only the first file is considered. If this file does not have a [flint] section, no project specific configuration is loaded.

If the ignore option is not in the configuration and not in the arguments, only the error codes E226 and E241/E242 are ignored (see below).

Message codes

The convention of Flint is to assign a code to each error or warning, like the pep8 tool. These codes are used to configure the list of errors which are selected or ignored.

Each code consists of an upper case ASCII letter followed by three digits. The recommendation is to use a different prefix for each plugin.

A list of the known prefixes is published below:

• E***/W***: pep8 errors and warnings
• F***: PyFlakes codes (see below)
• C9**: McCabe complexity plugin flint-mccabe
• N8**: Naming Conventions plugin pep8-naming

The original PyFlakes does not provide error codes. Flint patches the PyFlakes messages to add the following codes:

Original projects

Thank you to the authors of the various projects which are the building blocks of Flint:

• pep8: https://github.com/jcrocholl/pep8
• pyflakes: https://launchpad.net/pyflakes
• flake8: https://bitbucket.org/tarek/flake8

Links

• pep8 documentation
• flake8 documentation
• flint on GitHub

Changelog