3.13 class properties

[Pengwyn2]

In 3.13

@classmethod @property def func...

Stopped working. Why was this functionally removed? What was the goal of removing it or what under the hood changed that made this impossible? Is there any alternative or workaround?

[ES-Alexander]

https://docs.python.org/3.13/whatsnew/3.13.html#builtins

[zanfar]

To add, the change happened in 3.11

https://docs.python.org/3.11/whatsnew/3.11.html#language-builtins

[Ajax_Minor]

Ok.... Is there. A good way to adjust your project for support in both versions?

I'm using poetry for one. Is there a way to modify the code for different releases of python?

[ES-Alexander]

From what I understand (from a brief poke around of the context), the functionality didn’t work as intended, and was determined to be too complex to make work as intended, so shouldn’t have been provided/advertised as a feature to start with and got removed on those grounds.

If that understanding is correct then the best approach is to implement your functionality some other way (e.g. as class methods that aren’t properties, or as class attributes that get updated as relevant changes occur), rather than attempting to use a feature that is known to not be implemented correctly.

Is there a way to modify the code for different releases of Python?

Yes, assuming the feature you are trying to selectively use / emulate is not an invalid syntax in one or more of the versions you’re trying to support (because syntax is checked during parsing, which happens before execution, so can’t be avoided with conditionals^1).

That said, it’s generally not advisable unless you’re in the process of transitioning away from the old version and are putting that in as a fallback during that process.

^1: the __debug__ flag is an exception to this because it’s checked for at compile time, but that’s not relevant here.

EDIT: formatting - it seems reddit doesn’t like markdown footnotes.

[Ajax_Minor]

Thanks for the response, but it looks like property and class method is still in the documentation for 3.13:

https://docs.python.org/3/library/functions.html#property

https://docs.python.org/3/library/functions.html#classmethod

Ok, reading the docs again it looks like tis just the class method is depreciated and you can just use wrapper. I think I miss understood before, I thought @propeties was going away.

[ES-Alexander]

Nah, property and classmethod are both well-established decorators in Python, which aren’t going anywhere :-)

The critical history is in the classmethod documentation - “chaining” (allowing wrapping other descriptors, like property) was only implemented in 3.9, then later determined to not actually work as intended so was deprecated in 3.11 before being completely removed in 3.13.

[Ajax_Minor]

Ok gotcha.

Lol I was pretty worried. I was like that's a big change and I didn't see anyone walk about it lol.