this post was submitted on 05 Jan 2024
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Python

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Don't use Python's property (www.b-list.org)
submitted 10 months ago by jnovinger to c/python
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[–] [email protected] 18 points 10 months ago (1 children)

Tl;dr: don't use @property during design, it's almost certainly the wrong pattern. But use it to retrofit a method to a value.

[–] [email protected] 2 points 10 months ago

Yup. I pretty much only use it if I need to ensure new values are valid or provide a default value.

I do the same in other languages, like C# and JavaScript. Properties are cool, but should be quite rare.

[–] [email protected] 12 points 10 months ago (1 children)

this is a method, and always was a method, I just wanted it to look like an attribute for aesthetic reasons

I think "aesthetic reasons" is an oversimplification. There are certain assumptions a developer makes when reading some code that uses properties. While these assumptions are not clearly defined and may differ per developer, I think there is a common core.

(1) There are no side-effects. The object is not mutated (or any other object), no IO takes place.

(2) The time and space complexity is O(1).

(3) The result is consistent. Consequent calls to the property should return the same value unless there is a mutation between them.

[–] [email protected] 5 points 10 months ago

The combination of properties 1 and 3 makes it a pure function, which is also useful in compiled or jittable languages because it allows for a variety of optimizations.

[–] [email protected] 5 points 10 months ago* (last edited 10 months ago)

(tried to delete this comment but somehow didn't work, I re-read the article and have a different outlook, sorry for the low effort comment)

[–] [email protected] 1 points 10 months ago

Nah, I think I'll continue to.