I'm happy to assign this to myself, and volunteer to work on it next week :D

I'm happy to assign this to myself, and volunteer to work on it next week :D

Thanks for volunteering!

Sure, that's a fine one to support. In general, when adding features to piplite, I would suggest:

• try to match as closely as possible as what a "real" %pip install would do in IPython
  • so -i and --index-url
• support parsing of said feature as a line of -r requirements.txt
• add it as a site-level configurable in the kernel section of jupyter-lite.json
  • this has been discussed elsewhere (Allow to install extra packages from extra indexes from jupyter-lite.json #158, pre-install packages concurrently #164), and likely makes the most sense as something like:

{
  "jupyter-lite-schema-version": 0,
  "jupyter-config-data": {
    "appName": "JupyterLite Pyodide Kernel",
    "litePluginSettings": {
      "@jupyterlite/pyodide-kernel-extension:kernel": {
        "pipliteInstallDefaultOptions": {
          "indexUrls": ["http://..."]
        }
      }
    }
  }
}

Of note, until micropip 0.9.0+ lands in a pyodide release, there will be some fairly surprising behavior with under-specified installs, or %pip calls that occur in the same cell as imports due to the auto-import behavior. So:

%pip install thing-i-want-but-also-in-pyodide -i http://wherever
import some_thing_provided_by_that_package

vs

%pip install thing-i-want-but-also-in-pyodide -i http://wherever

and then

import some_thing_provided_by_that_package

Custom indexes are not included in this, as no upstream list of wheels provide importable names, to my knowledge.