python实现堆栈和队列代码片段

coding=utf-8
一端进行插入和删除运算。这一端被称为栈顶，相对地，把另一端称为栈底
class Stack():
    def __init__(self,size):
        self.size=size
        self.top=0
        self.val = []
    def push(self,data):
        if self.isfull():
            return 'The Stack is full'
        else:
            self.val.append(data)
            self.top=self.top+1
            return self.val
    def pop(self):
        if self.isempty():
            return 'The Stack is empty'
        else:
            self.val.pop(-1)
            self.top=self.top-1
            return self.val
    def length(self):
        return len(self.val)

    def isfull(self):
        if self.top==self.size:
            return True

    def isempty(self):
        if self.top==0:
            return True
    def string(self):
        return str(self.val)

coding=utf-8
队列在表的前端进行删除操作(队头)，后端进行插入操作(队尾)

class Queue():
    def __init__(self,size):
        self.size=size
        self.tail=0
        self.head=0
        self.que = []

    def append(self,data):
        if self.isfull():
            return 'The Queue is full'
        else:
            self.que.append(data)
            self.tail=self.tail+1
            return self.que           
    def pop(self):
        if self.isempty():
            return 'The Queue is empty'
        else:
            self.que.pop(0)
            self.head=self.head+1
            return self.que        
    def length(self):
        return len(self.que)

    def isfull(self):
        if self.tail-self.head==self.size:
            return True

    def isempty(self):
        if self.tail==self.head:
            return True
    def string(self):
        return str(self.que)

堆栈调用截图​

队列调用截图