Closest implementation for enums with fields in pyO3

Question

As of PyO3 version 0.18.1, only fieldless enums are supported.

What are the potential implementations to support enums with fields using PyO3 if implemented manually?? pyclass is of no use here (Correct me if I am wrong).

For instance if I have to implement for following enum?

pub enum Prop {
    Str(String),
    I32(i32),
    I64(i64),
    U32(u32),
    U64(u64),
    F32(f32),
    F64(f64),
    Bool(bool),
}

Please suggest.

https://github.com/PyO3/pyo3/discussions/2959 – iamsmkr Feb 18 '23 at 15:33 — iamsmkr, Feb 18 '23 at 15:33

score 1 · Answer 1 · answered Mar 10 '23 at 20:05

Copied from github.

The problem with this approach is that its not very pythonic. It would only be ideal if user could provide list of Prop as dictionary instead. I have managed to implement it as follows:

use pyo3::prelude::*;
use std::collections::HashMap;

#[derive(FromPyObject, Debug)]
pub enum Prop {
    Int(usize),
    String(String),
    Vec(Vec<usize>),
}

#[pyfunction]
pub fn get_props(props: HashMap<String, Prop>) -> PyResult<()> {
    let v = props.into_iter().collect::<Vec<(String, Prop)>>();
    for i in v {
        println!("K = {}, V = {:?}", i.0, i.1)
    }
    Ok(())
}

From python:

import pyo3_example

pyo3_example.get_props({
                   "name": "Shivam Kapoor", 
                   "age": 35,  
                   "hobbies": [1, 2, 3]
                 })
# K = name, V = String("Shivam Kapoor")
# K = age, V = Int(35)
# K = hobbies, V = Vec([1, 2, 3])

Closest implementation for enums with fields in pyO3

1 Answers1