Python数据结构——栈的链表实现

自定义链表实现栈的数据结构，代码如下：

 1 class Stack:
 2     def __init__(self):
 3         self._first = None
 4     def push(self,item):
 5         self._first = _Node(item,self._first)
 6     def pop(self):
 7         self._first = self._first.next        
 8     def isEmpty(self):
 9         return self._first is None
10 class _Node:
11     def __init__(self,item,next):
12         self.item = item
13         self.next = next
14         
15 def main():
16     stack = Stack()
17     stack.push("a")
18     stack.push("b")
19     stack.push("c")
20     print(stack._first.item)
21     print(stack._first.next.item)
22     print(stack._first.next.next.item)
23         
24 if __name__ == "__main__": main() 
运行结果：
>> c
>> b
>> a