如何使用Python实现链表的回文判断

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

def isPalindrome(head):
    slow = head
    fast = head

    # find the midpoint of the linked list
    while fast and fast.next:
        slow = slow.next
        fast = fast.next.next

    # reverse the second half of the linked list
    prev = None
    current = slow

    while current:
        next_node = current.next
        current.next = prev
        prev = current
        current = next_node

    # compare the first and second half of the linked list
    p1 = head
    p2 = prev

    while p2:
        if p1.data != p2.data:
            return False
        p1 = p1.next
        p2 = p2.next

    return True

# create a linked list
head = Node('p')
head.next = Node('i')
head.next.next = Node('d')
head.next.next.next = Node('a')
head.next.next.next.next = Node('n')
head.next.next.next.next.next = Node('c')
head.next.next.next.next.next.next = Node('o')
head.next.next.next.next.next.next.next = Node('d')
head.next.next.next.next.next.next.next.next = Node('e')
head.next.next.next.next.next.next.next.next.next = Node('.com')

# test if the linked list is palindrome
print(isPalindrome(head))  # True