Use this like git cherry except it outputs the log messages of commits in head that are not in upstream. It could be useful for summarinzing changes or writing release notes.

git-cherry-log

#!/usr/bin/env python3
# -*- Mode: python; coding: utf-8 -*-
# ---------------------------------------------------------------
# Copyright © 2015, 2022 Jason J.A. Stephenson <jason@sigio.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# ---------------------------------------------------------------

import subprocess, sys

def gather_args():
    args = { "upstream": None, "head": None, "limit": None }
    if len(sys.argv) > 1:
        args["upstream"] = sys.argv[1]
    if len(sys.argv) > 2:
        args["head"] = sys.argv[2]
    if len(sys.argv) > 3:
        args["limit"] = sys.argv[3]
    return args
    

def gather_commits(upstream=None, head=None, limit=None):
    args = ["git", "cherry"]
    if upstream:
        args.append(upstream)
    if head:
        args.append(head)
    if limit:
        args.append(limit)
    with subprocess.Popen(args, stdout=subprocess.PIPE) as git:
        commits = git.stdout.read().decode('utf8').splitlines()
    return commits

def get_log(commit):
    with subprocess.Popen(["git", "log", "-n 1", "--pretty=fuller", commit], stdout=subprocess.PIPE) as git:
        log = git.stdout.read().decode('utf8')
    return log

def main():
    cherryArgs = gather_args()
    for cherry in gather_commits(**cherryArgs):
        if cherry.startswith('+ '):
            print(get_log(cherry[2:42]))

if __name__ == "__main__":
    main()