原文
当函数的参数不确定时，可以使用args 和kwargs，args 没有key值，**kwargs有key值。
这个和Python的函数方法特性有关系.
**kwargs,函数可接受以参数名(key值)配对的无序的参数赋值
*args,有序无名参数数量可变的参数集.
*args
def fun_var_args(farg, *args):
print "arg:", farg
for value in args:
print "another arg:", value
fun_var_args(1, "two", 3) # *args可以当作可容纳多个变量组成的list
输出:
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被视为key， 感觉**kwargs可以当作容纳多个key和value的dictionary
输出:
arg: 1
another keyword arg: myarg2: two
another keyword arg: myarg3: 3
另外一种用法
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)
输出:
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)
输出:
arg1: 1
arg2:"two"
arg3:3
