Prints out the most changed files in a repo

gitlog.py

import os
counts = {}
for hash in os.popen('git log --all --format=%H'):
    hash = hash.strip()
    os.system('git checkout {}'.format(hash))
    for fname in os.popen('git diff --name-only HEAD^ HEAD'):
        fname = fname.strip()
        counts[fname] = counts.get(fname, 0) + 1
print('Most changed files:')
print('-------------------')
for fname, count in sorted(counts.items(), key=lambda x: x[1], reverse=True):
    print('{}: {}'.format(count, fname)