def postsubtree(self):
        """Postorder iterator over the subtrees.

        Warning: As always, do not use this iterator in a for loop while altering
        the structure of the tree."""

        if self:
            for subtree in self.childs:
                for tree in subtree.postsubtree():
                    yield tree
            yield self
Postorder iterator over the subtrees.

        Warning: As always, do not use this iterator in a for loop while altering
        the structure of the tree.
recipes/Python/136529_Trees_and_more_trees/recipe-136529.py