list-authors.py

import subprocess
import json
import sys
import os

try:
    REPO_MAPPING_FILE = sys.argv[1]
except IndexError:
    print("Error: no REPO_MAPPING_FILE passed as command line argument")
    sys.exit(1)

REPO_MAPPING_FILE = os.path.abspath(REPO_MAPPING_FILE)
basedir = os.path.dirname(REPO_MAPPING_FILE)

with open(REPO_MAPPING_FILE) as f:
    repos = list(json.load(f))

authors = set()
for repo in repos:
    cmd = ['hg', 'log', '--template', '{author}\n']
    output = subprocess.check_output(cmd, cwd=os.path.join(basedir, repo)).decode('utf8')
    authors = authors.union(output.splitlines())

authors_map = os.path.join(basedir, 'authors.map')
if os.path.exists(authors_map):
    print(
        "%s already exists. " % authors_map
        + "If you are sure you want to replace it, please "
        + "delete it and run this script again"
    )
    sys.exit(1)

with open(authors_map, 'wb') as f:
    for author in authors:
        if '@' in author and ' <' in author:
            # Already a valid git author:
            git_author = author
        elif '@' in author:
            # Need to prepend a username, use the email prefix:
            git_author = author.strip('<>').split('@', 1)[0] + ' <' + author + '>'
        else:
            # Need to append an email address, use devnull@localhost:
            git_author = author + ' <devnull@localhost>'
        f.write(u'"{}"="{}"\n'.format(author, git_author).encode('utf-8'))