pre-commit

#!/usr/bin/env python2
from __future__ import with_statement
import os
import shutil
import subprocess
import sys
import tempfile
import re

try:
    from pygments.console import colorize
except ImportError:
    colorize = lambda x, y: y


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


def main():
    files = (file for file in system(
        'git', 'diff', '--name-only', '--staged', '--diff-filter=AM'
        ).splitlines() if file.endswith('.py'))

    tempdir = tempfile.mkdtemp()

    for name in files:
        filename = os.path.join(tempdir, name)
        filepath = os.path.dirname(filename)
        if not os.path.exists(filepath):
            os.makedirs(filepath)
        with file(filename, 'w') as f:
            system('git', 'show', ':' + name, stdout=f)
    output = system('pep8', '.', cwd=tempdir)
    shutil.rmtree(tempdir)
    if output:
        output = re.sub(r'(.*):(\d+):(\d+)', colorize('blue', r'\1') + " " +
                        colorize('darkblue', r'\2') + ":" +
                        colorize('darkgreen', r'\3'), output)
        output = re.sub(r'(E\d{3}) (.*)', colorize('red', r'\1') +
                        " " + colorize('darkred', r'\2'), output)
        output = re.sub(r'(W\d{3}) (.*)', colorize('yellow', r'\1') +
                        " " + colorize('darkyellow', r'\2'), output)
        print colorize('red',
            '-----------------------------------\n'
            'Commit refused - pep8 not respected\n'
            '-----------------------------------\n')
        print output
        sys.exit(1)


if __name__ == '__main__':
    main()