Leetcode 'NoneType' 对象没有属性 'next'

Question

我正在解决这个问题，但出现错误：

AttributeError: 'NoneType' object has no attribute 'next'

有人可以帮助我指出正确的方向吗？

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> ListNode:
while (True):
headA = headA.next      # advance '1' step in list_A {this is the error line}
if (headA == headB):    # check for equality
return headA
headB = headB.next      # advance '1' step in list_B

Answer 1

当您到达链表的末尾时，即当headANone时，就会获得错误。