Nested class structure #542
Description
- cattrs version: cattrs==23.2.3
- Python version: python=3.11.2
- Operating System: OSX/Linux
Description
I want to use cattrs to (un)strcuture classes.
What I Did
import cattr
import attr
from cattrs.strategies import configure_tagged_union, include_subclasses
@attr.s(frozen=True, auto_attribs=True)
class A:
pass
@attr.s(frozen=True, auto_attribs=True)
class B1(A):
b: str
@attr.s(frozen=True, auto_attribs=True)
class B2(A):
b: str
a: A
CONVERTER = cattr.Converter()
union_strategy = partial(configure_tagged_union, tag_name="type_name")
include_subclasses(A, CONVERTER, union_strategy=union_strategy)
if __name__ == "__main__":
instance = B1(b="1")
r = CONVERTER.unstructure(instance)
CONVERTER.structure(r, A)
instance2 = B2(b="2", a=B1(b="1"))
r2 = CONVERTER.unstructure(instance2)
CONVERTER.structure(r2, A)
In the example above, we can (un)structure a B1 instance (e.g. instance) correctly. However, for a B2 instance (e.g. instance2), I can see catter unstructure it correctly, r2 looks correctly. However, I got B2(b='2', a=A()) back when I structure the r2 as A, which does not equal to the original instance2.