download.py 文件源码

def __init__(self, *args, **kwargs):
        super(SafeFileCache, self).__init__(*args, **kwargs)

        # Check to ensure that the directory containing our cache directory
        # is owned by the user current executing pip. If it does not exist
        # we will check the parent directory until we find one that does exist.
        # If it is not owned by the user executing pip then we will disable
        # the cache and log a warning.
        if not check_path_owner(self.directory):
            logger.warning(
                "The directory '%s' or its parent directory is not owned by "
                "the current user and the cache has been disabled. Please "
                "check the permissions and owner of that directory. If "
                "executing pip with sudo, you may want sudo's -H flag.",
                self.directory,
            )

            # Set our directory to None to disable the Cache
            self.directory = None