YAML roundtrip not working correctly

Hello, I am using hydra-zen to save config yaml files, ship them over to another system, and then load them back in and instantiate them. However, load_from_yaml is not working as expected - it loads back in a DictConfig rather than a hydrazen type and thus none of the type validation + coercion works when instantiating the loaded yaml. This is particularly an issue for enum types.

Repro:

import omegaconf
from omegaconf import MISSING, OmegaConf
import dataclasses
from enum import Enum

from hydra_zen import instantiate, builds, save_as_yaml, load_from_yaml, to_yaml

class Color(Enum):
    red = "RED"
    blue = "BLUE"

@dataclasses.dataclass
class Example:
    color: Color =  MISSING
    number: int = MISSING
    
    
built = builds(Example, color="blue", number="3")


print(type(built))
print(built)
print(instantiate(built))

save_as_yaml(built, "saved.yaml")
loaded = load_from_yaml("saved.yaml")

print()
print(type(loaded))
print(loaded)
print(instantiate(loaded))

The first 3 prints make sense:

<class 'type'>
<class 'types.Builds_Example'>
Example(color=<Color.blue: 'BLUE'>, number=3)

Proper type validation and coercion is done. When the yaml is saved and loaded back in however, type validation + coercion does not happen, since load_from_yaml returns a DictConfig rather than a type. The results of instantiate do not match. From the last 3 prints:

<class 'omegaconf.dictconfig.DictConfig'>
{'_target_': '__main__.Example', 'color': 'blue', 'number': 3}
Example(color='blue', number=3)

As you can see, Example is instantiated with the string blue rather than the enum <Color.blue: 'BLUE'>.

[petosa]

@Jasha10 thank you for this suggestion - it does seem to address my cases. I guess the only inconvenience is that I need to have special handling via builds for enums. I will try it out in my project and re-open if I run into more errors. Appreciate all the help!

[Jasha10]

One workaround, which does not rely on OmegaConf’s implicit conversion of str to Enum, is to call builds(Color, value="BLUE") so as to create an object whose _target_ points to Color:

import dataclasses
from enum import Enum
from hydra_zen import builds, instantiate, load_from_yaml, save_as_yaml
from omegaconf import MISSING

def pp(x):
    print(x, "::", type(x))

class Color(Enum):
    red = "RED"
    blue = "BLUE"

@dataclasses.dataclass
class Example:
    color: Color = MISSING
    number: int = MISSING

built = builds(Example, color=builds(Color, value="BLUE"), number="3")

pp(instantiate(built))

save_as_yaml(built, "saved.yaml")
loaded = load_from_yaml("saved.yaml")

pp(instantiate(loaded))

print()
pp(loaded)

$ python script.py
Example(color=<Color.blue: 'BLUE'>, number=3) :: <class '__main__.Example'>
Example(color=<Color.blue: 'BLUE'>, number=3) :: <class '__main__.Example'>

{'_target_': '__main__.Example', 'color': {'_target_': '__main__.Color', 'value': 'BLUE'}, 'number': 3} :: <class 'omegaconf.dictconfig.DictConfig'>

Here are 3 specific situations where the proposed solution does not work (can attach some code snippets later if that’d help).

I believe my proposal above should work around the 3 situations you mentioned, @petosa.