python語言之參數(shù)args與kwargs介紹

*args: 看例子及注釋

# *: 輸入的是位置參數(shù),例如: 1,2 , 輸出的是元組(1,2)
def args(*args):
return args

def test_args():
v = args()
assert () == v, 'args 空參數(shù)錯誤'

v = args(1, 2)
assert (1, 2) == v, 'args 1 tuple error'

params = (1, )
# *: 輸入的是序列, 輸出的是位置參數(shù), 1,2,
v = args(*params)
assert (1, ) == v, 'args 1 tuple error'

params = (1, 2, 3)
v = args(*params)
assert (1, 2, 3) == v, 'args 3 tuple error'

params = [1, 2, 3]
v = args(*params)
assert (1, 2, 3) == v, 'args 3 list error'

# set 也可以用set((1,2,3))初始化
params = {1, 2, 3}
v = args(*params)
assert (1, 2, 3) == v, 'args 3 set error'

params = range(1, 4)
v = args(*params)
assert (1, 2, 3) == v, 'args range(1,4) error'

params = 'a'
v = args(*params)
assert ('a', ) == v, 'args 1 str error'

params = 'a', 'b'
v = args(*params)
assert ('a', 'b') == v, 'args 1 str error'

2.**kwargs: 看例子及注釋

# **輸入的是命名位置參數(shù),例如: a=1,b=2 , 輸出的是字典{'a':1,'b':2}
def kwargs(**kwargs):
return kwargs

def test_kwargs():
v = kwargs()
assert {} == v, 'kwargs 空參錯誤'

v = kwargs(a=1, b=2)
assert {'a': 1, 'b': 2} == v, 'kwargs 傳a=1格式錯誤'

param = {'a': 1, 'b': 2}
# **: 輸入的是字典, 輸出的是命名位置參數(shù): a=1,b=2
v = kwargs(**param)
assert {'a': 1, 'b': 2} == v, 'kwargs 傳字典錯誤'



審核編輯：劉清