简单Queue实现 python语言

class Node:
	def __init__(self,data):
		self.data=data
		self.next=None

class Queue:
	def __init__(self):
		self.rear=None
		self.front=None
		self.r=0
		self.f=0
	def isEMpty(self):
		if self.r==self.f:
			print("The queue is empty")
		else:
			print("The queue is not empty")
	def push(self,data):
		if self.f==self.r:
			q=Node(data)
			self.rear=q
			self.front=q
			self.r=0
			self.f=1
		else:
			q=Node(data)
			self.rear.next=q
			self.rear=q
			self.f+=1
	def pop(self):
		if self.r==self.f:
			print("The Queue is empty")
			#return false
		else:
			self.front=self.front.next
			self.f=self.f-1;
	def top(self):
		if self.r==self.f:
			print("empty")
		else:
			print(self.front.data)