Python的队列

# -*- coding:utf-8 -*-
'''
定义一个队列Queue
'''
class Queue(object):
def __init__(self,size):
self.queue = []
self.size = size
self.head = -1
self.tail = -1

def isEmpty(self):
if self.head == self.tail:
return True
else:
return False

def isFull(self):
if self.tail - self.head + 1 == self.size:
return True
else:
return False

def inQueue(self,content):
if self.isFull():
print "Queue is full,can't contain any item any more."
else:
self.queue.append(content)  #入队时，将元素新增到队列中
self.tail += 1              #入队时，队首指针不变，队尾指针递增1

def outQueue(self):
if self.isEmpty():
print "Queue is empty,no item need to out."
else:
self.queue.pop(0)   #出队列：每次出队列后删除队首元素
self.head += 1      #出队列时，队首指针递增1，对位指针不变

def display(self):
print "Queue = ",self.queue
print "Size = ",len(self.queue)
print "Head = %d,Tail = %d\n"%(self.head,self.tail)

#测试出队入队操作、队满时入队、队空时出队
q = Queue(4)
print "----------入队操作----------"
for i in range(5):
q.inQueue(i)
q.display()
print "----------出队操作----------"
for i in range(6):
q.outQueue()
q.display()

”’

运行结果：

———-入队操作———-

Queue = [0]

Size = 1

Head = -1,Tail = 0

Queue = [0, 1]

Size = 2

Head = -1,Tail = 1

Queue = [0, 1, 2]

Size = 3

Head = -1,Tail = 2

Queue is full,can’t contain any item any more.

Queue = [0, 1, 2]

Size = 3

Head = -1,Tail = 2

Queue is full,can’t contain any item any more.

Queue = [0, 1, 2]

Size = 3

Head = -1,Tail = 2

———-出队操作———-

Queue = [1, 2]

Size = 2

Head = 0,Tail = 2

Queue = [2]

Size = 1

Head = 1,Tail = 2

Queue = []

Size = 0

Head = 2,Tail = 2

Queue is empty,no item need to out.

Queue = []

Size = 0

Head = 2,Tail = 2

Queue is empty,no item need to out.

Queue = []

Size = 0

Head = 2,Tail = 2

Queue is empty,no item need to out.

Queue = []

Size = 0

Head = 2,Tail = 2

”’