How to git cat-file using exclusively Python?

Question

我正在尝试读取提交哈希及其父哈希，以便从

.git/

目录构建提交图。目前，我有这样的东西：

import zlib
import os

...

    for current, subs, files in os.walk('.'):
        for filename in files:
            
            # in format ##/#{38}
            
            path = os.path.join(current, filename)[2:]

            # 'info/' and 'pack/' exist
            # don't worry about packed files
            # assume empty (excluding . and ..)

            with open(path, 'rb') as file:
                
                # returns bytes object
                # assuming UTF-8 encoding (default) vs. legacy
                # https://git-scm.com/docs/git-commit#_discussion
                # .decode() also defaults to utf-8
                
                print(zlib.decompress(file.read()).decode())

然而，我注意到这不是我想要的。上面的代码旨在最终遍历所有

.git/objects/

并将提交及其父母解析为一个列表，以帮助我构建提交图。截至目前，

zlib

减压似乎没有按照我喜欢的方式产生输出。我已经阅读了 Pro Git 中的相关部分，特别是：git-scm.com/book/en/v2/Git-Internals-Git-Objects，其中包含针对 Ruby 的说明。我如何在 Python 中完成此操作？