PyO3/pyo3 · error · syn::Error

useless `get` - the struct is already annotated with `get_al

Error message

useless `get` - the struct is already annotated with `get_all`

What it means

When a #[pyclass] is annotated with get_all, every field is automatically exposed as a getter; a per-field #[pyo3(get)] is then redundant and the macro (build_py_class) reports DUPE_GET at the field's span.

Source

Thrown at pyo3-macros-backend/src/pyclass.rs:332

            let mut results = Vec::new();

            if let Some(attr) = args.options.set_all {
                results.push(Err(syn::Error::new_spanned(attr, UNIT_SET)));
            };
            if let Some(attr) = args.options.get_all {
                results.push(Err(syn::Error::new_spanned(attr, UNIT_GET)));
            };

            results
        }
    }
    .into_iter()
    .try_combine_syn_errors()?;

    if let Some(attr) = args.options.get_all {
        for (_, FieldPyO3Options { get, .. }) in &mut field_options {
            if let Some(old_get) = get.replace(Annotated::Struct(attr)) {
                return Err(syn::Error::new(old_get.span(), DUPE_GET));
            }
        }
    }

    if let Some(attr) = args.options.set_all {
        for (_, FieldPyO3Options { set, .. }) in &mut field_options {
            if let Some(old_set) = set.replace(Annotated::Struct(attr)) {
                return Err(syn::Error::new(old_set.span(), DUPE_SET));
            }
        }
    }

    impl_class(&class.ident, &args, doc, field_options, methods_type, ctx)
}

enum Annotated<X, Y> {
    Field(X),
    Struct(Y),

View on GitHub (pinned to ac9b6899d3)

Solutions

Remove the per-field #[pyo3(get)] attributes on fields where get_all already applies
Remove get_all if only some fields should be getters
Convert fields that need different visibility handling to explicit per-field annotations and drop get_all

Example fix

// before
#[pyclass(get_all)]
struct Point {
    #[pyo3(get)]
    x: f64,
    y: f64,
}
// after
#[pyclass(get_all)]
struct Point {
    x: f64,
    y: f64,
}

Defensive patterns

Strategy: validation

Validate before calling

# CI lint: flag #[pyo3(get)] inside structs whose pyclass has get_all
# grep -A2 'pyclass(.*get_all' -r src/ | grep 'pyo3(get)' && exit 1

Prevention

When introducing get_all, remove all per-field #[pyo3(get)] in the same change
Keep one visibility convention per struct: all-fields or per-field, not both
Run cargo check/clippy on PRs to catch macro errors early

When it happens

Trigger: Combining #[pyclass(get_all)] with #[pyo3(get)] on one or more fields of the struct.

Common situations: Refactoring a class to get_all without removing old per-field get annotations; copy-pasting field attributes from another struct.

Related errors

AI-assisted analysis of PyO3/pyo3@ac9b6899d3 (2026-09-05). Data as JSON: /api/errors/23051454f589ce89. Report an issue: GitHub.