[FR] Provide public is_editable API to check package install mode

[janosh]

What's the problem this feature will solve?

The location of some data files in my package changes based on whether it's PyPI or editable install. I need a programmatic way to check in the package's own code if it's installed in --editable mode.

Describe the solution you'd like

A private API for this already exists in pip.

Alternative Solutions

There is an SO question with 4x as many upvotes as the highest-rated question (despite having 5 answers), indicating there's a need for this but no good existing method.

Additional context

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct

[abravalheri]

If I am not mistaken, you can already use importlib.metadata to read the direct_url.json file that contains a recording of how the package was installed.

[janosh]

Thanks, I didn't know about this! This is working great!

import json
from importlib.metadata import Distribution

direct_url = Distribution.from_name("pkg-name").read_text("direct_url.json")
pkg_is_editable = json.loads(direct_url).get("dir_info", {}).get("editable", False)

[abravalheri]

@janosh, I think it is not fully documented, but if I am not wrong the distribution.origin attribute will also give you the contents of direct_url.json as a dict (already parsed from the JSON file).

(Probably depends on the version of importlib.metadata you have, or if you are using the backfill importlib_metasdata, because the property was introduced a couple of months ago)

[janosh]

I briefly tried that but got AttributeError from distribution.origin. I have importlib-metadata 6.8.0.

Looks like origin was added in 6.11.