1 #!/usr/bin/env python 2 # --------------------------------------- 3 # author : Geng Jie 4 # email  : gengjie@outlook.com 5 # 6 # Create Time: 2016/3/16 22:05 7 # ---------------------------------------- 8  9 10 class Node():11     def __init__(self, data):12         self.data = data13         self.next = None14 15 16 class LinkedList:17     def __init__(self):18         self.head = None19         self.tail = None20 21     def append(self, data):22         node = Node(data)23         if self.head is None:24             self.head = node25             self.tail = node26 27         else:28             self.tail.next = node29             self.tail = node30 31     def is_zero(self):32         if self.head is None:33             return True34         return False35 36     def len(self):37         if self.head is None:38             return 'Empty'39         else:40             count = 041             while self.head:42                 self.head = self.head.next43                 count += 144             return count45 46     def iter(self):47         if not self.head:48             return49 50         cur = self.head51         yield cur.data52         while cur.next:53             cur = cur.next54             yield cur.data55 56     def insert(self, idx, value):57         cur = self.head58         cur_idx = 059         while cur_idx < idx - 1:60             cur = cur.next61             if cur is None:62                 raise Exception('List length less than index')63             cur_idx += 164         node = Node(value)65         node.next = cur.next66         cur.next = node67         if node.next is None:68             self.tail = node69 70     def remove(self, idx):71         cur = self.head72         cur_idx = 073         while cur_idx < idx - 1:74             cur = cur.next75             if cur is None:76                 raise Exception('List length less than index')77             cur_idx += 178         cur.next = cur.next.next79         if cur.next is None:80             self.tail = cur81 82 83 if __name__ == '__main__':84     linked_list = LinkedList()85     for i in range(10):86         linked_list.append(i)87 88     print(linked_list.len())89 90     # print(linked_list.is_zero())91     # linked_list.insert(3, 30)92     # linked_list.remove(4)93     # for node in linked_list.iter():94     #     print(node)