forcing positional and keyword arguments in a python function

consider this arbitrary function:

def f(user_id: str, /, message, *, channel: str) -> bool:
    pass

/ means everything to its left must be passed positionally. so user_id cannot be passed as a keyword argument

f("123", "hello", channel="general")     # ok
f(user_id="123", message="hello", channel="general")  # TypeError

message is a normal argument. you can pass it positionally or as a keyword. * means everything to its right must be passed as keyword arguments.

f("123", "hello", channel="general")     # ok
f(user_id="123", message="hello", channel="general")  # TypeError

You violate these rules and python raises a TypeError TypeError