python如何实现堆栈与队列的实例详解

class Stack():      def init(self,size):          self.size=size;          self.stack=[];          self.top=-1;      def push(self,ele):  #入栈之前检查栈是否已满          if self.isfull():              raise exception("out of range");          else:              self.stack.append(ele);              self.top=self.top+1;      def pop(self):             # 出栈之前检查栈是否为空          if self.isempty():              raise exception("stack is empty");          else:              self.top=self.top-1;              return self.stack.pop();            def isfull(self):          return self.top+1==self.size;      def isempty(self):          return self.top==-1;

#!/usr/bin/python   from stack import Stack  s=Stack(20);  for i in range(3):      s.push(i);  s.pop()  print s.isempty();

class Queue():      def init(self,size):          self.size=size;          self.front=-1;          self.rear=-1;          self.queue=[];      def enqueue(self,ele):  #入队操作          if self.isfull():              raise exception("queue is full");          else:              self.queue.append(ele);              self.rear=self.rear+1;      def dequeue(self):      #出队操作          if self.isempty():              raise exception("queue is empty");          else:              self.front=self.front+1;              return self.queue[self.front];      def isfull(self):          return self.rear-self.front+1==self.size;      def isempty(self):          return self.front==self.rear;        q=Queue(10);  for i in range(3):      q.enqueue(i);  print q.dequeue();  print q.isempty();