keyword-only-arguments.md

Function arguments that can only be used a keywords, not positional arguments

You can define a keyword-only function in python by using a * (everything afterwards will be keyword-only). This can make the meaning of function arguments much clearer, compare:

my_function(my_data, False, 4, 16, None)

and:

my_function(my_data, shuffle=False, num_workers=4, batch_size=16, output_file=None)

You'd define this as:

def my_function(my_data, *, shuffle, num_workers, batch_size, output_file):
    ...

You can also have positional-only arguments, but you probably don't need to do that.

Via: Richard