python之数据结构链表实现方式

#!/usr/bin/env python
# ---------------------------------------
# author : Geng Jie
# email  : gengjie@outlook.com
#
# Create Time: 2016/3/16 22:05
# ----------------------------------------


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


class LinkedList:
    def __init__(self):
        self.head = None
        self.tail = None

    def append(self, data):
        node = Node(data)
        if self.head is None:
            self.head = node
            self.tail = node

        else:
            self.tail.next = node
            self.tail = node

    def is_zero(self):
        if self.head is None:
            return True
        return False

    def len(self):
        if self.head is None:
            return 'Empty'
        else:
            count = 0
            while self.head:
                self.head = self.head.next
                count += 1
            return count

    def iter(self):
        if not self.head:
            return

        cur = self.head
        yield cur.data
        while cur.next:
            cur = cur.next
            yield cur.data

    def insert(self, idx, value):
        cur = self.head
        cur_idx = 0
        while cur_idx < idx - 1:
            cur = cur.next
            if cur is None:
                raise Exception('List length less than index')
            cur_idx += 1
        node = Node(value)
        node.next = cur.next
        cur.next = node
        if node.next is None:
            self.tail = node

    def remove(self, idx):
        cur = self.head
        cur_idx = 0
        while cur_idx < idx - 1:
            cur = cur.next
            if cur is None:
                raise Exception('List length less than index')
            cur_idx += 1
        cur.next = cur.next.next
        if cur.next is None:
            self.tail = cur


if __name__ == '__main__':
    linked_list = LinkedList()
    for i in range(10):
        linked_list.append(i)

    print(linked_list.len())

    # print(linked_list.is_zero())
    # linked_list.insert(3, 30)
    # linked_list.remove(4)
    # for node in linked_list.iter():
    #     print(node)