[$] Positional-only parameters for Python

Arguments can be passed to Python functions by position or by keyword—generally both. There are times when API designers may wish to restrict some function parameters to only be passed by position, which is harder than some think it should be in pure Python. That has led to a PEP that is meant to make the situation better, but opponents say it doesn't really do that; it simply replaces one obscure mechanism with another. The PEP was assigned a fairly well-known "BDFL delegate" (former BDFL Guido van Rossum), who has accepted it, presumably for Python 3.8.