queue.py 文件源码

def prepend(self, container):
        """Insert objects at the start of the container"""
        if not isinstance(container, collections.MutableSequence):
            container = [container]

        container.reverse()

        for x in container:
            if self._current != x:
                try:
                    self._container.remove(x)
                except ValueError:
                    pass
                self._container.appendleft(x)

        try:
            self._container.remove(self._current)
            self._container.appendleft(self._current)
        except ValueError:
            pass

        if self._current is None and any(self._container):
            self._current = self._container[0]