Add pip completion documentation

[sepehr-rs]

Fixes #13536

[sepehr-rs]

Hi @notatallshaw,
I tried fixing the pre-commit issue, but it’s still showing the same error. Could you please take a closer look at the files and see if you can fix it? Thanks so much! :)

[sepehr-rs]

Hi @notatallshaw, just checking in, do you have any updates on this?

[notatallshaw]

I've checked out locally and reproduced the CI errors, I've added comments to help, let me know if you need me to push these commits or if you can handle it.

[sepehr-rs]

Thanks a lot for the feedback!
I’ll work on fixing these issues, would love your feedback again once I push the updates.

[sepehr-rs]

pre-commit.ci autofix

[sepehr-rs]

Hi @notatallshaw, any updates?

[notatallshaw]

I've never used this feature and am unfamiliar with how to use it.

Just reading the docs you've added: https://pip--13542.org.readthedocs.build/en/13542/cli/pip_completion/ I still don't know how to use this feature.

The feature outputs some code to the stdout, and then what? What am I supposed to do with that? Or is the command doing something else?

[sepehr-rs]

pip completion is supposed to provide the user with a script to enable autocompletion. Typically, users set it up by adding something like this to their shell configuration file (e.g. .bashrc, .zshrc, etc.):

eval "$(pip completion --bash)"
# or
eval "$(pip completion --zsh)"

That way, the shell sources the completion code on startup.

[pfmoore]

I think the point here is that if we're going to document this, we need to include enough information for people who aren't familiar with how completion works to set it up "from scratch". That's going to involve having shell-specific instructions for all the shells we support.

[notatallshaw]

we need to include enough information for people who aren't familiar with how completion works to set it up "from scratch".

Yes exactly, I don't find the current "Examples" section particularly helpful, I would rather see "Example Setups" for each shell supported, so for the Bash example I would prefer to see something like:

echo 'eval "$(pip completion --bash)"' >> ~/.bashrc

If that's a way to add it to Bash.