flake8 git pre-commit hook

pre-commit

#!/usr/bin/env python
# inspired by http://tech.myemma.com/python-pep8-git-hooks/ 
from __future__ import with_statement
import re
import subprocess
import sys


def system(*args, **kwargs):
    kwargs.setdefault('stdout', subprocess.PIPE)
    proc = subprocess.Popen(args, **kwargs)
    out, err = proc.communicate()
    return out


def main():
    modified = re.compile('^[AM]+\s+(?P<name>.*\.py)', re.MULTILINE)
    files = system('git', 'status', '--porcelain')
    files = modified.findall(files)

    output = system('flake8', "--ignore=E501,F401", *files)
    if output:
        print output,
        sys.exit(1)


if __name__ == '__main__':
    main()