zero or one argument

[snippsat]

There is a problem with *args and **kwargs regarding the task.

to accept zero or one argument

There is no limit for that in *args and **kwargs

Just add:

>>> @limit_args(1)
... def func(*args):
...     if not args:
...         args = 'default'
...     return args

>>> func()
'default'

>>> func('hello')
('hello',)

>>> func('hello', 'world')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 5, in new_f
TooManyArguments: 1 args accepted at most, 2 args passed
1 args accepted at most, 2 args passed

>>> @limit_args(1)
... def something(**kwargs):
...     if kwargs:
...         for key, value in kwargs.items():
...             print(f'{key} is {value}')
...     else:
...         print('nothing to see here')

>>> something(place="London")
place is London

>>> something(place="London",  wetness="raining heavily")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 5, in new_f
TooManyArguments: 1 args accepted at most, 0 args passed
1 args accepted at most, 0 args passed

The missing code for that.

class TooManyArguments(Exception):
    pass

def limit_args(n):
    def limit_decorator(func):
        def new_f(*args, **kwargs):
            if len(args or kwarg) > n:
                raise TooManyArguments(f"{n} args accepted at most, {len(args)} args passed")
            return func(*args, **kwargs)
        return new_f
    return limit_decorator

But this going a little overboard,as the simple solution shown solve  that task.