Missing __init_subclass__ and __set_name__ magic methods in the user guide

[Divy1211]

Bug Description

• The __set_name__ magic method is missing from https://pyo3.rs/v0.21.2/class/protocols#descriptors
• The __init_subclass__ magic method is also missing from https://pyo3.rs/v0.21.2/class/protocols (Not quite sure which section __init_subclass__ should go into)

(Details for both methods: https://peps.python.org/pep-0487/#proposal)

Both magic methods seem to work in PyO3, so it looks like it's just the documentation for them that is missing from the user guide. Here's the code that I got to work for reference:

__set_name__:

#[pymethods]
impl MapValidate {
    fn __set_name__(&mut self, _owner: &Bound<'_, PyType>, name: &str) {
        self.name = name.to_string()
    }
}

__init_subclass__:

#[pymethods]
impl BaseStruct {
    #[classmethod]
    fn __init_subclass__(cls: &Bound<'_, PyType>) -> PyResult<()> {
        // code here
    }
}

Your operating system and version

Windows 10 Home 22H2 Build 19045.4291

Your Python version (python --version)

3.10.11

Your Rust version (rustc --version)

1.71.1

Your PyO3 version

0.21.2

How did you install python? Did you use a virtualenv?

• python.org
• created a venv using python -m venv venv

[davidhewitt]

This is deliberate, though the docs don't necessarily make it super clear. If it's not in the list in the docs then PyO3 doesn't need to do anything special with it and Python will handle it fine anyway.

[Divy1211]

This is deliberate, though the docs don't necessarily make it super clear. If it's not in the list in the docs then PyO3 doesn't need to do anything special with it and Python will handle it fine anyway.

Ahh, I see I see, I was confused because I (incorrectly) believed that PyO3 needs to deliberately support each magic method for them to work. Glad to hear that's not the case!