[Python] Combine `Protocol` with base class requirement, type intersection

I want to express some type which inherits from nn.Module. I would do so as follows:

ModuleType = TypeVar("ModuleType", bound=nn.Module)


At the same time, I want to express that it has an __init__ function of a certain format. I would do so using Protocol, as follows:

class InitWithCfgProtocol(Protocol):
def __init__(self, cfg: dict):
...


Now, how can I express a type which has both properties? Basically an intersection of ModuleType and InitWithCfgProtocol. Is this possible?

Further, how can this again be expressed as a TypeVar, such that I can use it as a template argument for a Generic? Like this:

ModuleInitWithCfgType = TypeVar(...) # ?


@dataclass
class ModuleFactory(Generic[ModuleInitWithCfgType]):
module_class: Type[ModuleInitWithCfgType]

def make(self, cfg: dict) -> ModuleInitWithCfgType:
return self.module_class(cfg)


In this example, I want to have proper checks (via PyCharm, mypy or similar) for:

• self.module_class(cfg) - it should warn when I pass wrong arguments
• factory = ModuleFactory(MyModule) - it should warn when I pass a wrong MyModule class

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