#!/usr/bin/env python
# coding:utf-8
'''
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黄哥Python培训 黄哥改写
Python 3
P148页代码
'''
queue = []
def enQ():
queue.append(input('Enter new queue element: '))
def deQ():
if len(queue) == 0:
print('Cannot dequeue from empty queue!')
else:
print('Removed [', queue.pop(0), ']')
def viewQ():
print(str(queue))
def showmenu():
prompt = """
(E)nqueue
(D)equeue
(V)iew
(Q)uit
Enter choice: """
done = 0
while not done:
chosen = 0
while not chosen:
try:
choice = input(prompt)[0]
except (IndexError, EOFError, KeyboardInterrupt):
choice = 'q'
print('\nYou picked: [%s]' % choice)
if choice not in 'devq':
print('invalid option, try again')
else:
chosen = 1
if choice == 'q':
done = 1
if choice == 'e':
enQ()
if choice == 'd':
deQ()
if choice == 'v':
viewQ()
if __name__ == '__main__':
showmenu()