class Stack():
    def __init__(self):
        self.element = []
    # 入栈
    def push(self,item):
        self.element.append(item)
    # 出栈
    def pop(self):
        if self.element:
            self.element.pop()
        else:
            raise LookupError('stack is error')
    # 判空
    def is_empty(self):
        return bool(self.element)
    # 返回栈顶元素
    def top(self):
        return self.element[-1]

if __name__ == '__main__':
    stack = Stack()
    print(stack.is_empty())
    stack.push(1)
    stack.push(2)
    stack.push(3)
    print(stack.element)
    stack.pop()
    print(stack.element)
    print(stack.is_empty())
    print(stack.top())

运行结果：