Python中*args 和**kwargs的用法

http://blog.csdn.net/chenjinyu_tang/article/details/8136841

好久沒有學習python了，應為工作的需要，再次拾起python，喚起記憶。

當函數的參數不確定時，可以使用*args 和**kwargs，*args 沒有key值，**kwargs有key值。

還是直接來代碼吧，廢話少說

?

def?fun_var_args(farg,?*args):??
????print?"arg:",?farg??
????for?value?in?args:??
????????print?"another?arg:",?value??
??
fun_var_args(1,?"two",?3)?#?*args可以當作可容納多個變量組成的list??

result:

?

arg:?1??
another?arg:?two??
another?arg:?3??

?

**kwargs:

def?fun_var_kwargs(farg,?**kwargs):??
????print?"arg:",?farg??
????for?key?in?kwargs:??
????????print?"another?keyword?arg:?%s:?%s"?%?(key,?kwargs[key])??
??
??
fun_var_kwargs(farg=1,?myarg2="two",?myarg3=3)?#?myarg2和myarg3被視為key，?感覺**kwargs可以當作容納多個key和value的dictionary??

result:

?

arg:?1??
another?keyword?arg:?myarg2:?two??
another?keyword?arg:?myarg3:?3??

也可以用下面的形式：

?

?

def?fun_var_args_call(arg1,?arg2,?arg3):??
????print?"arg1:",?arg1??
????print?"arg2:",?arg2??
????print?"arg3:",?arg3??
??
args?=?["two",?3]?#list??
??
fun_var_args_call(1,?*args)??

result：

?

?

arg1:?1??
arg2:?two??
arg3:?3??

?

def?fun_var_args_call(arg1,?arg2,?arg3):??
????print?"arg1:",?arg1??
????print?"arg2:",?arg2??
????print?"arg3:",?arg3??
??
kwargs?=?{"arg3":?3,?"arg2":?"two"}?#?dictionary??
??
fun_var_args_call(1,?**kwargs)??

result：

?

?

arg1:?1??arg2:"two"??arg3:3??
arg1:?1??
arg2:"two"??
arg3:3??