数据结构：链表（python版）续：带有尾节点引用的单链表

 #!/usr/bin/env python
 # -*- coding:utf-8 -*-

 from chapter3.single_linked_list import LNode,LinkedListUnderflow,LList
 import random

 class LList1(LList):
     def __init__(self):
         LList.__init__(self)
         self._rear = None

     #表头插入
     def prepend(self, elem):
         if self._head is None:
             self._head = LNode(elem)
             self._rear = self._head
         else:
             self._head = LNode(elem, self._head)

     #表尾插入
     def append(self, elem):
         if self._head is None:
             self._head = LNode(elem)
             self._rear = self._head
         else:
             self._rear.next = LNode(elem)
             self._rear = self._rear.next

     #表头删除
     def pop(self):
         if self._head is None:
             raise LinkedListUnderflow("in pop")
         e = self._head.elem
         self._head = self._head.next
         return e
         #self._rear不变仍然指向最后一个元素

     #表尾删除
     def pop_last(self):
         p = self._head
         if p is None:
             raise LinkedListUnderflow("in pop_last")
         if p.next is None:
             self._head = None
         while p.next.next:
             p = p.next
         e = p.next.elem
         p.next = None
         self._rear = p
         return e

 if __name__=="__main__":
     mlist1 = LList1()
     mlist1.prepend(98)
     mlist1.printall()

     for i in range(10,20):
         mlist1.append(random.randint(1,20))

     mlist1.printall()

     for i in mlist1.filter(lambda y: y%2 == 0):
         print(i)