Python 用列表模拟队列 queue.py

'''
Created on 2011-7-23

@author: Administrator
'''
#!/usr/bin/env python

queue=[]

def enQ():
    queue.append(raw_input('Enter New string :').strip())

def deQ():
    if len(queue)==0:
        print 'Cannot pop from an empty queue !'
    else:
        print 'Removed  [' , `queue.pop(0)` , '] '

def viewQ():
    print queue

CMDs={'e':enQ,'d':deQ,'v':viewQ}

def showmenu():
    pr="""
(E)nqueue
(D)nqueue
(V)iew
(Q)uit
Enter choice:"""
    while True:
        while True:
            try:
                choice=raw_input(pr).strip()[0].lower()
            except:
                choice='q'
            print '\n You pickde: [%s]' %choice
            if choice not in 'devq':
                print 'Invalid option ,try again'
            else:
                break
        if choice =='q':
            break
        CMDs[choice]()
if __name__== '__main__' :
    showmenu()