栈

直接通过List就可以实现

class Stack:
    # 模拟栈
    def __init__(self):
        self.items = []
    def isEmpty(self):
        return len(self.items) == 0
    def push(self, item):
        self.items.append(item)
    def pop(self):
        return self.items.pop()
    def peek(self):
        if not self.isEmpty():
            return self.items[len(self.items) - 1]
    def size(self):
        return len(self.items)
if __name__ == "__main__":
    # 创建一个栈对象，并加入操作方法
    s = Stack()
    print(s.isEmpty())
    s.push(4)
    s.push('DOG')
    print(s.peek())
    s.push(True)
    print(s.size())
    print(s.isEmpty())
    s.push(8.4)
    print(s.pop())
    print(s.pop())
    print(s.size())