Handling defaults in dataclasses about mashumaro

[Fatal1ty]

Given your input:

logging:

YAML Loader produces {"logging": None} that is not correct for your Config scheme. Leaving the value blank means not an empty mapping but null. You should change it this way:

logging: {}

If for some reason you want to break the rules, you can handle this by the hook:

@dataclass
class Config(DataClassYAMLMixin):
    logging: LogLevel

    @classmethod
    def __pre_deserialize__(cls, d):
        if d.get('logging') is None:
            d['logging'] = {}
        return d


s = 'logging:'
config = Config.from_yaml(s)
print(config)  # Config(logging=LogLevel(level='INFO'))

[peku-jamf]

amazing, thanks for the clarification!