frompyobject: improve error message for tuple case

This commit is contained in:
David Hewitt 2022-06-01 07:43:42 +01:00
parent 2769963536
commit cfb91057af
3 changed files with 44 additions and 26 deletions

View File

@ -3,7 +3,7 @@ use crate::{
utils::get_pyo3_crate,
};
use proc_macro2::TokenStream;
use quote::quote;
use quote::{quote, format_ident};
use syn::{
parenthesized,
parse::{Parse, ParseStream},
@ -244,48 +244,33 @@ impl<'a> Container<'a> {
fn build_tuple_struct(&self, tups: &[FieldPyO3Attributes]) -> TokenStream {
let self_ty = &self.path;
let mut fields: Punctuated<TokenStream, syn::Token![,]> = Punctuated::new();
for (index, attrs) in tups.iter().enumerate() {
let field_idents: Vec<_> = (0..tups.len()).into_iter().map(|i| format_ident!("arg{}", i)).collect();
let fields = tups.iter().zip(&field_idents).enumerate().map(|(index, (attrs, ident))| {
let error_msg = format!("failed to extract field {}.{}", quote!(#self_ty), index);
let parsed_item = match &attrs.from_py_with {
None => quote!(
obj.get_item(#index)?.extract()
_pyo3::PyAny::extract(#ident)
),
Some(FromPyWithAttribute {
value: expr_path, ..
}) => quote! (
#expr_path(obj.get_item(#index)?)
#expr_path(#ident)
),
};
let extractor = quote!(
quote!(
#parsed_item.map_err(|inner| {
let py = _pyo3::PyNativeType::py(obj);
let new_err = _pyo3::exceptions::PyTypeError::new_err(#error_msg);
new_err.set_cause(py, ::std::option::Option::Some(inner));
new_err
})?
);
fields.push(quote!(#extractor));
}
let len = tups.len();
let msg = if self.is_enum_variant {
quote!(::std::format!(
"expected tuple of length {}, but got length {}",
#len,
s.len()
))
} else {
quote!("")
};
)
});
quote!(
let s = <_pyo3::types::PyTuple as _pyo3::conversion::PyTryFrom>::try_from(obj)?;
if s.len() != #len {
return ::std::result::Result::Err(_pyo3::exceptions::PyValueError::new_err(#msg))
}
::std::result::Result::Ok(#self_ty(#fields))
let (#(#field_idents),*) = obj.extract()?;
::std::result::Result::Ok(#self_ty(#(#fields),*))
)
}

View File

@ -291,9 +291,10 @@ impl<'a> IntoIterator for &'a PyTuple {
}
}
#[cold]
fn wrong_tuple_length(t: &PyTuple, expected_length: usize) -> PyErr {
let msg = format!(
"Expected tuple of length {}, but got tuple of length {}.",
"expected tuple of length {}, but got tuple of length {}",
expected_length,
t.len()
);

View File

@ -399,6 +399,21 @@ TypeError: failed to extract enum Foo ('TupleVar | StructVar | TransparentTuple
- variant StructWithGetItem (StructWithGetItem): 'a'
- variant StructWithGetItemArg (StructWithGetItemArg): 'foo'"
);
let tup = PyTuple::empty(py);
let err = Foo::extract(tup.as_ref()).unwrap_err();
assert_eq!(
err.to_string(),
"\
TypeError: failed to extract enum Foo ('TupleVar | StructVar | TransparentTuple | TransparentStructVar | StructVarGetAttrArg | StructWithGetItem | StructWithGetItemArg')
- variant TupleVar (TupleVar): expected tuple of length 2, but got tuple of length 0
- variant StructVar (StructVar): 'tuple' object has no attribute 'test'
- variant TransparentTuple (TransparentTuple): 'tuple' object cannot be interpreted as an integer
- variant TransparentStructVar (TransparentStructVar): failed to extract field Foo :: TransparentStructVar.a
- variant StructVarGetAttrArg (StructVarGetAttrArg): 'tuple' object has no attribute 'bla'
- variant StructWithGetItem (StructWithGetItem): tuple indices must be integers or slices, not str
- variant StructWithGetItemArg (StructWithGetItemArg): tuple indices must be integers or slices, not str"
);
});
}
@ -500,6 +515,23 @@ fn test_from_py_with_tuple_struct() {
});
}
#[test]
fn test_from_py_with_tuple_struct_error() {
Python::with_gil(|py| {
let py_zap = py
.eval(r#"("whatever", [1, 2, 3], "third")"#, None, None)
.expect("failed to create tuple");
let f = ZapTuple::extract(py_zap);
assert!(f.is_err());
assert_eq!(
f.unwrap_err().to_string(),
"ValueError: expected tuple of length 2, but got tuple of length 3"
);
});
}
#[derive(Debug, FromPyObject, PartialEq)]
pub enum ZapEnum {
Zip(#[pyo3(from_py_with = "PyAny::len")] usize),