1、打开Python开发工具IDLE，新建‘Stack.py’文件，并写代码如下：class Stack: def __init__(self): self.items 租涫疼迟= [] def isEmpty(self): return self.items == [] def length(self): return len(self.items) def push(self,item): self.items.append(item) def pop(self) return self.items.pop()这里先实现了构造函数，初始栈的列表为空，用list的append和pop方法实现入栈和出栈，好处在于时间复杂度均仅为O(1).
2、编写main函数如下;if __name__ == '__main__': stack = Stack() print (stack.isEmpty()) stack.push(1) stack.push(2) print (stack.isEmpty()) print (stack.length()) print (stack.pop())
3、F5运行程序，程序初始为空，先后入栈1，2，出栈时候2先出。TrueFalse22
4、继续编写peek函数，peek函数只是查看栈顶元素，在这里是栈内部的List的底。def peek(self): return self.items[-1]
5、peek函数还可以写成如下形式，同张虢咆噘时改写main以测试peek函数 def peek(self): return self.items[len(self.items)-1]足毂忍珩if __name__ == '__main__': stack = Stack() print (stack.isEmpty()) stack.push(1) stack.push(2) print (stack.isEmpty()) print (stack.length()) print (stack.pop()) print (stack.peek())
6、F5运行程序，打印出信息如下peek得到栈顶元素为1TrueFalse221
