I declare this post Off Topic. Please open another thread (preferably on python-ideas).
Everybody else, please don't respond to this particular post by the OP. On Wed, Jun 24, 2020 at 11:12 AM pylang <[email protected]> wrote: > Great timing! Last week I was trying to emulate a certain Rust example in > Python. > Rust has a way to implement families of classes without subclassing, > which I think could be a great addition to Python someday. I'll explain > below. > > Here is a Rust example (https://youtu.be/WDkv2cKOxx0?t=3795) > that demonstrates a way to implement classes without subclassing. > > # Rust Code > enum Shape { > Circle(f32), > Square(f32), > Rectangle(f32, f32) > } > > impl Shape { > fn area(self) -> f32 { > match self { > Shape::Circle(r) => 3.1 * r * r, > Shape::Square(l) => l * l, > Shape::Rectangle(l, w) => l * w > } > } > } > > fn main () { > let c = Shape::Circle(3.0); > let s = Shape::Square(3.0); > let r = Shape::Rectangle(3.0, 7.5); > println!("○しろまる {}", c.area()); > println!("□しろいしかく {}", s.area()); > println!("▭ {}", r.area()); > } > > # Output > ○しろまる 27.899998 > □しろいしかく 9 > ▭ 22.5 > > The general idea is: > - declare classes that share a certain type > - extend common methods with a match-case style > > That's it. No sub-classing required. > > I wondered if someday, can we do this in Python? This match-case proposal > seems to fit well in this example. > > While I know this PEP does not focus on detailed applications, > does anyone believe we can achieve elegant class creation (sans > subclassing) with match-cases? > > > On Wed, Jun 24, 2020 at 2:04 PM Guido van Rossum <[email protected]> wrote: > >> On Tue, Jun 23, 2020 at 11:27 PM Emily Bowman <[email protected]> >> wrote: >> > I wonder if it's time to officially designate _ as a reserved name. >> >> Alas, it's too late for that. The i18n community uses _("message text") >> to mark translatable text. You may want to look into the gettext stdlib >> module. >> >> -- >> --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/> >> _______________________________________________ >> Python-Dev mailing list -- [email protected] >> To unsubscribe send an email to [email protected] >> https://mail.python.org/mailman3/lists/python-dev.python.org/ >> Message archived at >> https://mail.python.org/archives/list/[email protected]/message/P6EKIKFP6MX2N2KVFFCF4XUVVMSJ6Q5B/ >> Code of Conduct: http://python.org/psf/codeofconduct/ >> > -- --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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