How to annotate a class method parameter with the class it self [duplicate]
TreeNode is only defined after the class TreeNode body. Use from __future__ import annotations or child: 'TreeNode' to make a forward reference.
class TreeNode:
def __init__(
self,
element: Entity,
children=None
):
if children is None:
self.children = []
else:
self.children = children
self.element = element
def add_children(self, child: 'TreeNode'):
self.children.append(child)