python栈实现

1、直接利用list的pop,push来实现

#!/usr/bin/env python3
# encoding: utf-8

class Stack:
    def __init__(self):
        self.items = []

    def is_empty(self):
        return self.items == []

    def push(self, item):
        self.items.append(item)
    
    def pop(self):
        return self.items.pop()

    def peek(self):
        return self.items[-1]

    def size(self):
        return len(self.items)

if __name__ == "__main__":
    s = Stack()
    print(s.is_empty())
    s.push(4)
    s.push('dog')
    print(s.peek())
    s.push(True)
    print(s.size())
    print(s.is_empty())
    s.push(8.4)
    print(s.pop())
    print(s.pop())
    print(s.size())

　　2、现在【0】存放底，同样利用list来实现。

#!/usr/bin/env python3
# encoding: utf-8

class Stack:
    def __init__(self):
        self.items = []

    def is_empty(self):
        return self.items == []

    def push(self, item):
        self.items.insert(0, item)

    def pop(self):
        return self.items.pop(0)

    def peek(self):
        return self.items[0]

    def size(self):
        return len(self.items)

    s = Stack()
    print(s.is_empty())
    s.push(4)
    s.push('dog')
    print(s.peek())
    s.push(True)
    print(s.size())
    print(s.is_empty())
    s.push(8.4)
    print(s.pop())
    print(s.pop())
    print(s.size())