*args attribute in the middle of parameters

Question

I'm researching the effect of using *args in between a python function but I don't understand if the use case is practical or even possible, it is marked as error on my IDE.

def my_function(a, *args, b):
print(a)
print(args)
print(b)


my_function(1, 2, 3, 4, 5)

My output is the following:

Traceback (most recent call last):
  File "C:/Users/axel_/PycharmProjects/Python_Subject_Exam/3_new_exam_args_in_middle.py", line 10, in <module>
    my_function(1, 2, 3, 4, 5)
TypeError: my_function() missing 1 required keyword-only argument: 'b'

So, the *args must be ever at the end of parameters of any function, puting it at the midle is invalid python code right?

I also tested it at the end as intended:

def my_function(a, b, *args):
    print(a)
    print(args)
    print(b)


my_function(1, 2, 3, 4, 5)

Output:

1
(3, 4, 5)
2

Process finished with exit code 0

Answer 1

This pattern is used to force users to specify all parameters after *args, in your case you must set b. This would be accepted:

my_function(1, 2, 3, 4, 5, b=6)