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<2011-11-17> by Lorenzo

git pre-commit hook for Python and Javascript

Following a recent discussion on HN, I decided to share my own git pre-commit hook.


import os
import sys
import re
import subprocess

devnull = open(os.devnull, 'w')

def call(cmd):
    p = subprocess.Popen(cmd.split(),
    out, err = p.communicate()
    return out.decode('utf-8'), err.decode('utf-8'), p.returncode

def execute(cmd, silent=False):
    if silent:
        params = {
                'stdout': devnull,
                'stderr': devnull,
        params = {}

    retcode = subprocess.call(cmd.split(), **params)
    return retcode

def exists(cmd):
    return execute('which %s' % cmd, silent=True) == 0

def get_modified(ext):
    modified = re.compile('^(?:M|A).(?P<name>.*\.%s)' % ext)
    out, _, _ = call('git status --porcelain')
    modifieds = []
    for line in out.splitlines():
        match = modified.match(line.strip())
        if (match):
    return modifieds

It's a work-in-progress, so you can find the most updated version here. To use it, just drop it in your .git/hooks directory. At every git commit, it will run [pep8][4] and [pyflakes][5] on .py files, and [gjslint][6] on .js files.