Support for recursive data?

[masinc]

Python: 3.10.8
pyserde: 0.9.5

I defined the following class and an error occurred.

from dataclasses import dataclass
from serde import serde, field
from typing import Optional

@dataclass
class A:
    a: Optional['A'] # = field(skip_if_false=True)

# RecursionError
A = serde(A)

The field value is commented out, but a RecurtionError is raised in both case.

Rust Serde worked with similar recursive data structures.

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
pub struct A {
    a: Option<Box<A>>,
}

[yukinarit]

Hi @masinc, This is only the workaround I could come up with

from dataclasses import dataclass
from serde import serde, to_dict, from_dict
from typing import Optional
from typing import Generic, TypeVar

T = TypeVar('T')

@serde
@dataclass
class A(Generic[T]):
    a: Optional[T]

a = A(A(A(None)))
print(to_dict(a))
print(from_dict(A[A[A[int]]], {'a': {'a': {'a': None}}}))  # int in A[A[A[int]]] is a fake type

Output

{'a': {'a': {'a': None}}}
A(a=A(a=A(a=None)))

[masinc]

Thx @yukinarit.
Adding a custom deserializer field gave the expected behavior!

[yukinarit]

Published pyserde v0.9.6!