Bare asterisk in function arguments?

Question

What does a bare asterisk in the arguments of a function do?

When I looked at the pickle module, I see this:

pickle.dump(obj, file, protocol=None, *,         


        

Answer 1

Bare * is used to force the caller to use named arguments - so you cannot define a function with * as an argument when you have no following keyword arguments.

See this answer or Python 3 documentation for more details.