Python的elif语句

Python中没有switch/case语句,我们可以用elif语句来模拟它.

如:

if user.cmd == 'create':
    action = "create item"
elif user.cmd == 'delete':
    action = 'delete item'
elif user.cmd == 'update':
    action = 'update item'
else:
    action = 'invalid choice... try again!'

简化一下可以变为如下形式:

if user.cmd in ('create', 'delete', 'update'):
    action = '%s item' % user.cmd
else:
    action = 'invalid choice... try again!'

使用字典要比使用elif或者for循环快很多.