git-mailsort.py

#!/usr/bin/env python

import getopt
import mailbox
import sys


def parse_mailbox(filename, dry_run):
    mbox = mailbox.mbox(filename)
    sorted_messages = sorted(mbox, key=lambda x: x['subject'])
    for message in sorted_messages:
        print message['subject']

    if not dry_run:
        mbox.clear()
        for m in sorted_messages:
            mbox.add(m)
    mbox.close()

def main():
    try:
        opts, args = getopt.getopt(sys.argv[1:], "df:")
    except getopt.GetoptError as err:
        print str(err)
        sys.exit(2)

    dry_run = False
    filename = None
    for o, a in opts:
        if o == "-d":
            dry_run = True
        elif o == "-f":
            filename = a
        else:
            assert False, "unhandled option"

    if filename is None:
        print "filename not specified"
        sys.exit(2)

    parse_mailbox(filename, dry_run)

if __name__ == "__main__":
    main()