You can also disable positional handling via * to require keywords in function calls, e.g.:

    def add(*, l, r):
      return l + r
    
    add(l=1, r=2)
    >>> 3
    add(1, r=2)
    >>> [...]
    >>> TypeError: add() takes 0 positional arguments but 1 positional argument (and 1 keyword-only argument) were given

I believe 3.8 is adding / (I think) to do the same but for positional arguments, i.e., arguments you cannot give by keyword.

Just be careful not to use mutable objects as your default args.