Found the mypy bug: https://github.com/python/mypy/issues/4125
On Sat, Jun 26, 2021 at 7:35 PM Daniel Walker <[email protected]> wrote: > I wasn't looking at the type stub but cmd.py itself. It has > > PROMPT = '(Cmd) ' > ... > > class Cmd: > prompt = PROMPT > ... > > On Sat, Jun 26, 2021 at 6:04 PM Guido van Rossum <[email protected]> wrote: > >> On Sat, Jun 26, 2021 at 9:25 AM Daniel Walker <[email protected]> >> wrote: >> >>> I was recently using the cmd module for a project where my CLI >>> could connect to and interact with another host. I implemented prompt in >>> such a way that it would show the IP address when connected. I.e., >>> >>> class MyCmd(cmd.Cmd): >>> ... >>> >>> @property >>> def prompt(self) -> str: >>> if self.remote_host.connected(): >>> return f'> ({self.remote_host.ip}) ' >>> else: >>> return '> ' >>> >>> This worked perfectly fine... until I ran mypy. mypy complained >>> because, in cmd.Cmd, prompt is a class attribute. >>> >>> Looking at cmd.py, this seems like an odd design choice as all of the >>> references to cmd are through the instance (i.e., self.prompt). >>> >> >> You misread the typeshed stub. Where you see these lines in cmd.pyi >> >> class Cmd: >> prompt: str >> identchars: str >> ruler: str >> ... >> >> those are all instance attribute declarations. >> >> I think that you're running into a different mypy bug, which is that you >> can't override a plain attribute with a property in a subclass. >> >> I think there's already a bug for that in the mypy tracker, but I can't >> find it right now. >> >> -- >> --Guido van Rossum (python.org/~guido) >> *Pronouns: he/him **(why is my pronoun here?)* >> <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/> >> >
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