Python——栈的实现（面向对象法

class Stack():

    def __init__(self):
        self.stack = []

    def push(self,value):
        self.stack.append(value)
        return True

    def pop(self):
        #先判断栈是否为空
        if self.stack:
            item = self.stack.pop()
            return item
        else:
            return False

    def top(self):
        if self.stack:
            return self.stack[-1]
        else:
            return False

    def length(self):
        return len(self.stack)

    def view(self):
        return ','.join(self.stack)