Document that NETRC environment variable is supported

[wwuck]

What's the problem this feature will solve?

I was reading through the pip documentation for .netrc support and it doesn't appear to mention if there is any support for the NETRC environment variable.

It does say the .netrc support comes from requests and the stdlib netrc module but there is no documentation for NETRC environment variable in either the stdlib netrc docs or requests docs.

I did find a pull request in requests psf/requests#5643 which implements support for NETRC environment variable so I'm guessing that it also applies to pip?

Describe the solution you'd like

I would like to see the pip docs clarify whether or not the NETRC environment variable is supported for the pip netrc authentication.

Alternative Solutions

I can submit a PR to update pip docs if this NETRC support is clarified.

Additional context

The only documentation reference I can find anywhere mentioning NETRC is in the ftp documentation linked from the pip docs at https://www.gnu.org/software/inetutils/manual/html_node/The-_002enetrc-file.html but obviously that doesn't apply to anything python-related.

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[wwuck]

I can now see the docs update for requests mentions finding the netrc file at ~/.netrc, ~/_netrc and from NETRC environment variable. Is the ~/_netrc path supported on linux or is that only for Windows?

[uranusjr]

I believe _netrc is only for Windows (because in some versions of Windows you cannot start a filename with .). You should stick to .netrc if possible though.

[wwuck]

I'm planning on trying to use it in a Jenkins CI pipeline where I don't have access to ~/.netrc and will be temporarily copying the file out of the Jenkins credential store, so NETRC support is essential here.

[q0w]

I've used NETRC env for testing recently #10998

[notatallshaw]

I was worried this was requests specific behavior because it was only added to requests fairly recently but it seems httpx also supports it so hopefully it's commonly agreed upon for HTTP libraries:

• https://www.python-httpx.org/advanced/#netrc-support
• Respect the NETRC environment variable psf/requests#5643

[pfmoore]

Even so, I think this is covered by our comment that our network support is handled by requests. If it's not covered clearly enough in the requests documentation, then maybe you could ask there for it to be improved?

[notatallshaw]

As per the PR I linked above it seems to be documented in request's quickstart guide: https://docs.python-requests.org/en/latest/user/quickstart/#custom-headers

I wish the logic of how a netrc file was sourced and parsed was included in a specific netrc location like here: https://2.python-requests.org/en/master/user/authentication/#netrc-authentication (as this is the location when you search for "netrc" in their docs search and the quickstart guide doesn't appear at all). But that's just a wish, I can't contribute PRs right now until I've come to an agreement with my current employer.