_filefinder2.py 文件源码

def _path_importer_cache(cls, path):  # from importlib.PathFinder
            """Get the finder for the path entry from sys.path_importer_cache.
            If the path entry is not in the cache, find the appropriate finder
            and cache it. If no finder is available, store None.
            """
            if path == '':
                try:
                    path = os.getcwd()
                except FileNotFoundError:
                    # Don't cache the failure as the cwd can easily change to
                    # a valid directory later on.
                    return None
            try:
                finder = sys.path_importer_cache[path]
            except KeyError:
                finder = cls._path_hooks(path)
                sys.path_importer_cache[path] = finder

            return finder