Response is "falsy"

[Derkades]

Describe the bug

bool(web.Response()) evaluates to False. I suspect this is because Response inherits from MutableMapping.

This may cause confusion when checking for if response: instead of if response is not None.

To Reproduce

>>> response = web.Response()
>>> bool(response)
False
>>> response["a"] = 1
>>> bool(response)
True

Expected behavior

I personally think Response should always be "truthy".

Logs/tracebacks

N/A

Python Version

3.13.0

aiohttp Version

3.11.9

multidict Version

6.1.0

propcache Version

0.2.0

yarl Version

1.17.1

OS

Fedora 41

Related component

Server, Client

Additional context

No response

Code of Conduct

• I agree to follow the aio-libs Code of Conduct

[Dreamsorcerer]

It's a minor point, but feel free to make a PR to change it to True.

[asvetlov]

I prefer not to touch this behavior; otherwise I can ask: "why empty mapping is true-ish"?
In general, a check for None should be written as a is None or a is not None

[Derkades]

I do agree that is None should be preferred, but sometimes I get lazy and just check if response. Then it takes me a while for me to figure out the resulting bug, but that might just be me.

It is a breaking change, so I can understand not wanting to change the existing behaviour.

[Dreamsorcerer]

I still slightly agree that it should always be True. The mapping functionality is a minor part of the Response functionality, so I don't think it should define the bool state (I can't think of any use for this). But, I don't feel strongly about it.

[asvetlov]

Ok, let's do it.
Anybody wants to prepare a pull request?

[Derkades]

Sure, I will do it. Nice simple first contribution

[Derkades]

I see Application, which is also inherits from MutableMapping, already has __bool__ with return True and even a test to assert this behaviour. So there certainly is precedent