Python `pip install`缓存文件的ID字符串是如何计算的?

ID字符串是url的sha224哈希值(十六进制):

$ echo -n 'https://files.pythonhosted.org/packages/51/07/7e9266a59bb267b56c1f432f6416653b9a78dda771c57740d064a8aa2a44/pillow-10.2.0-cp312-cp312-win_amd64.whl' | openssl sha224 -hex
SHA2-224(stdin)= 5da855ed79847734593562113083d79c2634b1696f0d635c02984eb4

你没有指定你正在查看的pip版本,所以我查看了最新版本 https://github.com/pypa/pip 并搜索了'.body',找到了两个参考文献。最有希望的是file_cache.py:

    def get_body(self, key: str) -> IO[bytes] | None:
        name = self._fn(key) + ".body"
        try:
            return open(name, "rb")
        except FileNotFoundError:
            return None

然后你就跟着走 _fn() 到 encode() 最后是电话 get_body(cache_url) :

    def encode(x: str) -> str:
        return hashlib.sha224(x.encode()).hexdigest()

    def _fn(self, name: str) -> str:
        # NOTE: This method should not change as some may depend on it.
        #       See: https://github.com/ionrock/cachecontrol/issues/63
        hashed = self.encode(name)
        parts = list(hashed[:5]) + [hashed]
        return os.path.join(self.directory, *parts)

            body_file = self.cache.get_body(cache_url)