Python中的多功能参数
该*指定参数和**kwargs是通过一种方法多参数的函数。它们允许将可变数量的参数传递给函数。但是，请注意，不必仅将变量命名为*args或**kwargs。仅*是重要的。我们也可以将变量命名为*var或**named_vars。
*args的用法
*args用于将非关键字的可变长度参数列表发送到函数。
示例
Python 3.6.8 (default, Apr 25 2019, 21:02:35)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> def test_args(arg1, *argv):
... print("first argument :{}".format(arg1))
... for arg in argv:
... print("argument received :{}".format(arg))
...
>>> test_args('test1', 'test2', 'test3')
first argument :test1
argument received :test2
argument received :test3
>>>**kwargs的用法
**kwargs允许将关键字可变长度参数传递给方法。该**kwargs是为了处理使用的函数命名参数。
示例
Python 3.6.8 (default, Apr 25 2019, 21:02:35)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> def welcome_names(**kwargs):
... if kwargs:
... for key, value in kwargs.items():
... print("{} = {}".format(key, value))
...
>>> welcome_names(name="include_help")
name = include_help
>>>示例
Python 3.6.8 (default, Apr 25 2019, 21:02:35) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux Type "help", "copyright", "credits" or "license" for more information. >>> def test_multiple_args(arg1, arg2, arg3): ... print(arg1) ... print(arg2) ... print(arg3) ... >>>
现在，让我们使用*args作为上述函数，
>>> args = ['test1', 1,2] >>> test_multiple_args(*args) test1 1 2
现在，使用**kwargs
>>> kwargs = {"arg3": 3, "arg2": "two","arg1":5}
>>> test_multiple_args(**kwargs)
5
two
3
>>>