Convert hg commit hashes to git tags after using hg-git

git-mapfile-tags.py

import sys, os, os.path

def main(args):
    if len(args) == 2:
        return tags(os.path.abspath(args[1]))
    else:
        print 'Usage: <hg-repository-path>'

def tags(repo):
    if not os.path.exists(repo):
        raise ValueError('Path does not exist: %s' % repo)
    hgrepo = os.path.join(repo, '.hg')
    if not os.path.exists(repo):
        raise ValueError('Path does not exist: %s' % hgrepo)
    gitrepo = os.path.join(hgrepo, 'git')
    if not os.path.exists(gitrepo):
        raise ValueError('Path does not exist: %s' % gitrepo)
    gitmapfile = os.path.join(hgrepo, 'git-mapfile')
    if not os.path.exists(gitmapfile):
        raise ValueError('Path does not exist: %s' % gitmapfile)
    gitrefstags = os.path.join(gitrepo, 'refs', 'tags')
    if not os.path.exists(gitrefstags):
        raise ValueError('Path does not exist: %s' % gitrefstags)
    return proc(gitmapfile, gitrefstags)

def proc(gitmapfile, gitrefstags):
    with open(gitmapfile, 'rb') as mapfile:
        for line in mapfile.readlines():
            tags = line.strip().split()
            if len(tags) == 2:
                path = os.path.join(gitrefstags, tags[1])
                with open(path, 'wb') as tagfile:
                    tagfile.write(tags[0])
                    tagfile.write('\n')

if __name__ == '__main__':
    sys.exit(main(sys.argv))