storing dataclass member declarations into variables

I am calling a get_unit API that returns a json that contains info about a unit. The API supports sending a flag. For now let’s say the possible flags are basic, sensors, or last_update and depending on the flag, it returns data. I can provide multiple flags if I want
I want to read the json into a dataclass, but I don’t want to write a dataclass for each combination of flags. So my idea is to make a dataclass for each flag, and do “dynamic multiple inheritence” like mentioned in this question.

@dataclass
class SaUnitBasic(DataclassFromDict):
    _id: str = field_from_dict(default="")
    last_update: Union[dict, list, None] = field_from_dict(default_factory=list)
    counters: Union[dict, list, None] = field_from_dict(default_factory=dict)


@dataclass
class SaUnitUpdates(DataclassFromDict):
    _id: str = field_from_dict(default="")
    counters: Union[dict, list, None] = field_from_dict(default_factory=dict)


@dataclass
class SaUnitSensors(DataclassFromDict):
    _id: str = field_from_dict(default="")
    sensors: Union[dict, list, None] = field_from_dict(default_factory=list)

As you can see, some basic fields are defined whatever the flag like _id, and some can exist in different flags like counters.

Instead of rewriting the member definition each time (because I might change the default behavior, for example), is there a way to store it in a variable and reuse it like this?

_id_VAR =(_id: str = field_from_dict(default=""))
counters_VAR = (counters: Union[dict, list, None] = field_from_dict(default_factory=dict))
@dataclass
class SaUnitBasic(DataclassFromDict):
    _id_VAR
    last_update: Union[dict, list, None] = field_from_dict(default_factory=list)
    counters_VAR


@dataclass
class SaUnitUpdates(DataclassFromDict):
    _id_VAR
    counters_VAR


@dataclass
class SaUnitSensors(DataclassFromDict):
    _id_VAR
    sensors: Union[dict, list, None] = field_from_dict(default_factory=list)

I tried writing it as in the second example, but this is obviously wrong python syntax.