22 leetcode - Merge Two Sorted Lists

#!/usr/bin/python# -*- coding: utf-8 -*-'''英文:Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.中文:合并两个有序链表'''# Definition for singly-linked list.# class ListNode(object):#     def __init__(self, x):#         self.val = x#         self.next = Noneclass Solution(object):    def mergeTwoLists(self, l1, l2):        """        :type l1: ListNode        :type l2: ListNode        :rtype: ListNode        """        if not l1:            return l2        if not l2:            return l1        if l1.val < l2.val:            start = tmp = l1            l1 = l1.next        else:            start = tmp = l2            l2 = l2.next        while l1 and l2:            if l1.val < l2.val:                tmp.next = l1                l1 = l1.next            else:                tmp.next = l2                l2 = l2.next            tmp = tmp.next        if l1:            tmp.next = l1        if l2:            tmp.next = l2        return startif __name__ == "__main__":    s = Solution()