git-changelog

#!/usr/bin/env python

# git-changelog
#
# version 1.0, by John Wiegley
#
# The purpose of this code is to turn "git log" output into a complete
# ChangeLog, for projects who wish to begin using a ChangeLog, but haven't
# been.

import datetime
import string
import sys
import re

from subprocess import *

p = Popen("git log --stat %s" % string.join(sys.argv[1:], " "),
          shell = True, stdout = PIPE).stdout

line = p.readline()
while line:
    match = re.match("commit ([0-9a-f]+)", line)
    assert match
    hash_id = match.group(1)

    line = p.readline()

    match = re.match("Author: (.+)", line)
    assert match
    author = match.group(1)
    author = re.sub(" <", "  <", author)

    line = p.readline()

    match = re.match("Date: +(.+?) [-+][0-9]{4}", line)
    assert match
    # Tue Sep 30 05:43:49 2003 +0000
    date = datetime.datetime.strptime(match.group(1), '%a %b %d %H:%M:%S %Y')

    line = p.readline()         # absorb separator
    line = p.readline()

    log_text = ""
    while line and line != '\n':
        if not log_text:
            log_text += line[4:]
        else:
            log_text += "\t" + line[4:]

        line = p.readline()

    line = p.readline()

    files = []
    while line and line != '\n':
        match = re.match(" (.+?) +\\|", line)
        if match:
            files.append(match.group(1))
            line = p.readline()
        else:
            break

    line = p.readline()

    fp = Popen("fmt", shell = True, stdin = PIPE, stdout = PIPE)

    fp.stdin.write("\t* %s: %s\n" % (string.join(files, ",\n\t"), log_text))
    fp.stdin.close()
    log_text = fp.stdout.read()

    del fp

    print "%s  %s\n\n%s\t* commit %s\n" % \
        (date.strftime("%Y-%m-%d"), author, log_text, hash_id)

    line = p.readline()

# git-changelog ends here