util.py 文件源码

def __delitem__(self, key):
        # not efficient -- for convenience only
        try:
            index = self._index.pop(self._serialize_key(key))
            self._index = dict((k, i if i < index else i - 1) for k, i in self._index.items())
            self._items.pop(index)
        except KeyError:
            raise KeyError(str(key))