arg and keyword arg conflict: what to raise

[Skaperen]

i have a function which has keyword arguments for everything. two of them also could be given as regular positional arguments. it tests for something non-None given both ways for each. the intent is to raise an exception when the call is done wrong like this. which exception should i raise for this?

[Gribouillis]

Can you give an example of such code?

[ndc85430]

Why would you do that instead of either using one or the other?

[Skaperen]

Can you give an example of such code?

def foobar(*args,**kwargs):
    if len(args)>1 and 'foo' in kwargs:
        raise Foo('"foo" is given in both positional arguments (arg 2) and keyword arguments (foo=)')
    ...

---

Why would you do that instead of either using one or the other?

sometimes i want to use it one way or sometimes i want to use it the other way. i plan to post (a URL to) this code when it is done and initially tested.

[Gribouillis]

I would raise TypeError in such a case. For example

>>> def f():
...     pass
... 
>>> f(3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: f() takes 0 positional arguments but 1 was given

[Skaperen]

so, basically, the function being called the wrong way, is treating it as a type other than what it really is. i found a more like example random.choices() when used with an argument provided twice, raised TypeError, too. that's what i'll use.