python中的switch

1.
[code]class MyCommandDispatcher(object):
def do_a(self):
# do stuff

def do_b(self):
# do stuff

def do_5(self):
# do stuff

def default(self):
# do stuff

def switch(self, option):
getattr(self, 'do_' + str(option), self.default)()

d = MyCommandDispatcher()
d.switch('a')
d.switch(5)
[/code]
2.[code]
result = {
'a': lambda x: x * 5,
'b': lambda x: x + 7,
'c': lambda x: x - 2
}[value](x)
[/code]
3.if
elif
else