python可变参数 - *args, **kwargs

def foo(*args, **kwargs):
    print('args = ', args)
    print('kwargs = ', kwargs)
    print('---------------------------------------')

if __name__ == '__main__':
    foo(1, 2, 3, 4)
    foo(a = 1, b = 2, c = 3)
    foo(1, 2, 3, 4, a = 1, b = 2, c = 3)
    foo('a', 1, None, a = 1, b = '2', c = 3)

输出结果如下：

args =  (1, 2, 3, 4) 
kwargs =  {} 
--------------------------------------- 
args =  () 
kwargs =  {'a': 1, 'c': 3, 'b': 2} 
--------------------------------------- 
args =  (1, 2, 3, 4) 
kwargs =  {'a': 1, 'c': 3, 'b': 2} 
--------------------------------------- 
args =  ('a', 1, None) 
kwargs =  {'a': 1, 'c': 3, 'b': '2'} 
---------------------------------------

结论：
*args为元组可变参数，以非等号标志符提取
**kwargs为字典可变参数，以=号为标志符提取