Python keyword-only parameters

Similar to Python Positional-Only Parameters but the other way around: parameters placed on the right side of the * syntax parameter will be coerced into the keyword-only parameter type.

def f(a, *, b, c):
    print(a, b, c)

In the above excerpt, a can be given either as positional or keyword parameter. However, b and c do not have other options beside being pass through keyword arguments:

python> f(1, b=2, c=3)
1 2 3
python> f(a=1, b=2, c=3)
1 2 3

Should you try something else, it will most likely fails:

python> f(1, 2, 3)
TypeError: f() takes 1 positional argument but 3 were given

Notes:

• Python does not allow positional arguments after keyword arguments because of the left-side/right-side of the * operator thingy.
• *args are collecting as positional arguments.
• **kwargs are collecting as keyword-arguments.