234. palindrome linked list

# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class (object):
    def isPalindrome(self, head):
        """
        :type head: ListNode
        :rtype: bool
        """
        if not head:
            return True
        link_list = []
        p = head
        while p:
            link_list.append(p.val)
            p = p.next
    
        length = len(link_list)
        if length % 2 == 0:
            return link_list[:(length / 2)] == link_list[(length / 2):][::-1]
        else:
            return link_list[:(length / 2)] == link_list[(length / 2) + 1:][::-1]