stack.py

#!/usr/bin/env python

stack = []

def pushit():
 stack.append(raw_input('Enter new string: '))

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

def viewstack():
 print str(stack)

def showmenu():
 prompt = """
p(U)sh
p(O)p
(V)iew
(Q)uit

Enter choice: """

 done = 0
 while not done:

 chosen = 0
 while not chosen:
 try:
 choice = raw_input(prompt)[0]
 except (IndexError, EOFError, KeyboardInterrupt):
 choice = 'q'
 print '\nYou picked: [%s]' % choice
 if choice not in 'uovq':
 print 'invalid option, try again'
 else:
 chosen = 1

 if choice == 'q': done = 1
 if choice == 'u': pushit()
 if choice == 'o': popit()
 if choice == 'v': viewstack()

if __name__ == '__main__':
 showmenu()