*args和**kwargs的使用方法

• *args 用来将参数打包成tuple给函数体调用
• **kwargs 打包关键字参数成dict给函数体调用

def test_args(first, *args, **kwargs):
    print('Required argument: ', first)
    print('Optional argument: ', args)
    print('Optional argument: ', kwargs)

test_args(1, 2, 3, 4)
test_args(1, k1=2, k2=3, k3=4)
test_args(1, 2, k2=3, k3=4)

运行结果：

Required argument:  1
Optional argument:  (2, 3, 4)
Optional argument:  {}
===============================================
Required argument:  1
Optional argument:  ()
Optional argument:  {'k3': 4, 'k1': 2, 'k2': 3}
===============================================
Required argument:  1
Optional argument:  (2,)
Optional argument:  {'k3': 4, 'k2': 3}