When proxy_map contains None as value, the library will throw an exception, the proposed changes will fix the error:

proxy_map:
{'http://': Proxy('http://sys-proxy-rd-relay.xxxx.org:8119'), 'https://': Proxy('http://sys-proxy-rd-relay.xxxx.org:8119'), 'all://localhost': None}

Exception:
File /usr/local/lib/python3.11/dist-packages/httpx/_urlparse.py:411, in normalize_port(port, scheme) 409 port_as_int = int(port)
410 except ValueError:
--> 411 raise InvalidURL(f"Invalid port: {port!r}") 413 # See https://url.spec.whatwg.org/#url-miscellaneous 414 default_port = {"ftp": 21, "http": 80, "https": 443, "ws": 80, "wss": 443}.get( 415 scheme
416 )

InvalidURL: Invalid port: ':'

Summary

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.