Python 利用字典实现类似 java switch case 功能

def add():
    print('add')
def sub():
    print('sub')
def exit():
    print('exit')
choice = { '1' : add, '2' : sub, '3' : exit}
item = input('please input your number! ')
if item in choice:
    choice[item]()
运行结果:
please input your number! 2
sub