找出两个点间的所有路径

Question

问题遇到的现象和发生背景

找出两个点间的所有路径
有两段代码，我本来以为是一样的效果，结果不一样，请解答一下是为什么

用代码块功能插入代码，请勿粘贴截图

path = []
stack = []

def path_between_nodes(start, end):
    stack.append(start)
    if start == end:
       
        path.append(stack.copy())
        stack.pop()
  
    else:
        for nextPoint in neighbor[start]:
            if nextPoint not in: 
                path_between_nodes(nextPoint, end)
        stack.pop()
    return path

path = []
stack = []

def path_between_nodes(start, end):
    stack.append(start)
    if start == end:

        path.append(stack.copy())

    else:
        for nextPoint in neighbor[start]:
            if nextPoint not in stack:
                path_between_nodes(nextPoint, end)
                stack.pop()
    return path

Answer 1

差别很小吧，第一个代码等价于在return path之前stack.pop()，第二个代码是在运行path_between_nodes()之后，也就是return path之后再stack.pop()，感觉差别仅仅是stack的内容可能会不一样。能具体讲讲你看到的不一样的效果？