- 论坛徽章:
- 0
|
我完全按照教科书上写的程序,怎么执行不了的,程序如下 :
#!/usr/bin/env python
stack = []
def pushit():
stack.append(raw_input('Enter New string:').strip())
def popit():
if len(stack) == 0 :
print 'Cannot pop from an empty stack!'
else:
print 'Removed [',`stack.pop()` ,']'
def viewstack():
print stack
CMDs = {'u':pushit,'o':popit,'v':viewstack}
def showmenu():
pr = '''
p(U)sh
p(O)p
(V)iew
(Q)uit
Enter choice:'''
while True :
while True:
try:
choice = raw_input(pr).strip()[0].lower()
except (EOFError,KeyboardInterrupt,IndexError):
choice = 'q'
print '\nYou picked:[%s]' %choice
if choice not in 'uovq':
print 'Invalid option,try again'
else:
break
if choice == 'q':
break
CMDs[choice]()
if _name_ == '_main_':
showmenu()
执行之后报错:
[root@localhost python]# python stack.py
Traceback (most recent call last):
File "stack.py", line 37, in <module>
choice = raw_input(pr).strip()[0].lower()
NameError: name 'pr' is not defined |
|