python如何實現堆棧與隊列的實例詳解

class Stack(): 
 def init(self,size): 
 self.size=size; 
 self.stack=[]; 
 self.top=-1; 
 def push(self,ele): #入棧之前檢查棧是否已滿 
 if self.isfull(): 
 raise exception("out of range"); 
 else: 
 self.stack.append(ele); 
 self.top=self.top+1; 
 def pop(self): # 出棧之前檢查棧是否為空 
 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): #入隊操作 
 if self.isfull(): 
 raise exception("queue is full"); 
 else: 
 self.queue.append(ele); 
 self.rear=self.rear+1; 
 def dequeue(self): #出隊操作 
 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();