How do you type a function that takes a module as an input?

[Jacob-Flasheye]

I want to create a function that takes a module as an input:

import foo

def register_module(module: ???):
    ...

register_module(foo)

and I've tried looking around but cannot find anything about typing modules as input, probably because it's a uncommon use-case. I'll just on with using Any but it would be nice to know if there is a way to type this as well.

[Gobot1234]

You are looking for types.ModuleType

[Jacob-Flasheye]

Thanks for the quick answer!

[erictraut]

types.ModuleType won't provide any type checking within the function itself since types.ModuleType doesn't define any symbols within the module other than those that are common to all modules such as __name__ and __path__. If your function requires additional symbols to be present in the module, you can define a structural type in the form of a protocol class.

[Jacob-Flasheye]

Thanks for the follow-up!
I don't want to say I'm a typing newbie (have been using it a lot over the years, love the work!) but some concepts are kind hard to understand. How would I describe a module that has at least one attribute (member?) of a certain class in it?
Like in this example, how should ModuleWithGenerated be defined?:

# In generated_1.py
a = _Generated(1, 2, 3)
b = _Generated(4, 5, 6)

# In main.py
from typing import Protocol

import generated_1
import generated_2  # generated_2.py has no attributes of type _Generated

class ModuleWithGenerated(Protocol):
    ... # Must contain at least one _Generated attribute

def register_module(module: ModuleWithGenerated):
    ...

register_module(generated_1)  # OK
register_module(generated_2)  # NOT OK

I honestly don't think I have to type this properly because I'm checking the attribute type anyway, but I like to make the typing correct. Gives me a sense of pride and accomplishment!

[erictraut]

You can't express the concept "must contain at least one _Generated attribute" with a protocol class, but you can express concepts like "there must be an attribute called a whose type is _Generated" or "there must be a function called "foo" that has a particular signature.

[Jacob-Flasheye]

Gotcha. Suspected as much really, seems like a fairly unusual thing to do.