How to Format Git Patch Series as an MBOX File in Python

import re
from pathlib import Path


def format_patch_series_mbox(commits, output_path="series.mbox"):
    entries = []
    for idx, commit in enumerate(commits, start=1):
        subject = commit["subject"]
        author = commit["author"]
        email = commit["email"]
        date = commit["date"]
        body = commit["body"]

        entry = (
            f"From {email} {date}\n"
            f"From: {author} <{email}>\n"
            f"Date: {date}\n"
            f"Subject: [PATCH {idx:03d}/{len(commits):03d}] {subject}\n"
            f"\n"
            f"{body}\n"
            f"-- \n"
            f"---\n"
            f"---\n"
        )
        entries.append(entry)

    mbox_content = "\n".join(entries)
    Path(output_path).write_text(mbox_content, encoding="utf-8")
    return mbox_content


if __name__ == "__main__":
    commits = [
        {
            "subject": "Add user authentication",
            "author": "Alice Developer",
            "email": "alice@example.com",
            "date": "Mon, 03 Jun 2024 10:00:00 +0000",
            "body": "Implement login and session management.",
        },
        {
            "subject": "Fix password reset flow",
            "author": "Bob Maintainer",
            "email": "bob@example.com",
            "date": "Tue, 04 Jun 2024 14:30:00 +0000",
            "body": "Resolve redirect loop and add email validation.",
        },
    ]

    result = format_patch_series_mbox(commits)
    clean_subjects = re.findall(r"Subject:.*", result)
    for line in clean_subjects:
        print(line)