Have an option for allowing positional arguments.

[tomprince]

This is particular useful for classes with a single attribute. See for example

https://github.com/radix/effect/blob/0.1a11/effect/__init__.py#L242-249

[hynek]

I was thinking about something like that. A positional only without popping args off which would allow for faster constructors (but no cooperation with an own __init__?).

[tomprince]

I don't care about speed, simply usage.