def zip_location(filename: str) -> tuple[str, str] | None:
    """Split a filename into a zipfile / inner name pair.

    Only return a pair if the zipfile exists.  No check is made if the inner
    name is in the zipfile.

    """
    for ext in [".zip", ".whl", ".egg", ".pex"]:
        zipbase, extension, inner = filename.partition(ext + sep(filename))
        if extension:
            zipfile = zipbase + ext
            if os.path.exists(zipfile):
                return zipfile, inner
    return None
Split a filename into a zipfile / inner name pair.

    Only return a pair if the zipfile exists.  No check is made if the inner
    name is in the zipfile.

    
coverage/files.py