英文:
Using *args and **kwargs with special parameter in Python
问题
Reading the official document, I learned that I can use two special symbols / and * to specify positional and keyword arguments range.
When a function needs to receive variable arguments (*args), you can define it like this:
def function_args_s1(p1, p2, /, pk1, pk2, *, k1, k2, **kwargs):pass
Keyword variable arguments (**kwargs) work as expected.
but variable arguments (*args) encounter some errors.
def function_args_s2(p1, p2, *args, /, pk1, pk2, *, k1, k2):passSyntaxError: invalid syntax
def function_args_s3(p1, p2, /, pk1, pk2, *args, k1, k2):passpk1 and pk2 are no longer used as keyword parameters because they appear before *args.<details><summary>英文:</summary>Reading the [offical document](https://docs.python.org/3/tutorial/controlflow.html#special-parameters), I learned that I can use two special symbol `/` and `*` to specify positional and keyword arguments range.When function need to receive variable `arguments(*args)`, how to define this function?keyword variable `arguments(**kwargs)` works as expected.```pythondef function_args_s1(p1, p2, /, pk1, pk2, *, k1, k2, **kwargs):passfunction_args_s1(1, 2, 1, pk2=2, k1=1, k2=2, k3=3, k4=4)
but variable arguments(*args) meet some error.
def function_args_s2(p1, p2, *args, /, pk1, pk2, *, k1, k2):passSyntaxError: invalid syntax
def function_args_s3(p1, p2, /, pk1, pk2, *args, k1, k2):passpk1 and pk2 are no longer use keyword parameter because they before *args
答案1
得分: 1
*args参数在函数中捕获所有剩余的位置参数，这意味着它也执行了*的功能。
def function_args_s2(p1, p2, /, pk1, pk2, *args, k1, k2, **kwargs):print(args)print(kwargs)
然后
function_args_s2(1, 2, 3, 4, k1=5, k2=6)(){}function_args_s2(1, 2, 3, 4, 5, 6, k1=7, k2=8, kw1=9, kw2=10)(5, 6){'kw1': 9, 'kw2': 10}
英文:
The *args argument in a function is capturing all remaining positional argument, which means it also does what * does.
def function_args_s2(p1, p2, /, pk1, pk2, *args, k1, k2, **kwargs):print(args)print(kwargs)
Then
function_args_s2(1, 2, 3, 4, k1=5, k2=6)(){}function_args_s2(1, 2, 3, 4, 5, 6, k1=7, k2=8, kw1=9, kw2=10)(5, 6){'kw1': 9, 'kw2': 10}
答案2
得分: -1
不要在相同的签名中同时使用 *args 和 /。*args 允许多个参数，/ 不允许。
英文:
Do not have *args and / in the same signature. *args allows for multiple arguments, / does not.
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