Question about httpx.Client constructor parameter proxies

[chagui]

Hello,
Thanks for the great library!

I just ran into a mypy error for the following code.

def fun(proxies: httpx.Proxy | None) -> None:
    with httpx.Client(proxies=proxies):
        pass

error: Argument "proxies" to "Client" has incompatible type "Optional[Proxy]"; expected "Union[Union[URL, str], Proxy, Dict[Union[URL, str], Union[None, Union[URL, str], Proxy]]]"  [arg-type]
Found 1 error in 1 file (checked 1 source file)

I find this surprising because the httpx.Client constructor parameter proxies is advertised as optional:

• proxies - (optional) A dictionary mapping proxy keys to proxy
  URLs.

https://github.com/encode/httpx/blob/master/httpx/_client.py#L598-L599

It's also the default value for the parameter:

proxies: ProxiesTypes = None,

https://github.com/encode/httpx/blob/master/httpx/_client.py#L626

Should the type be changed to typing.Optional[ProxiesTypes] or am I missing something?

I could not find any existing issue related to this but if I somehow miss it feel free to point me to it and close this one 😇

[florimondmanca]

Hi @chagui, are you using mypy --strict? If so, this might be related to #2092.

How does def fun(proxies: httpx.Proxy = None) do ?

[chagui]

Indeed mypy was run with strict mode enabled, so it's a duplicate of the mentioned issue. Thanks 🙏

[florimondmanca]

I'm tentatively moving this to Discussions for now, since we try to keep Issues for well-defined work items.