IMPORT_PATH for pyckel

[Dorsug]

Is your feature request related to a problem? Please describe.
There is no way to specify import path when using the pyckel wraper because the NICKEL_IMPORT_PATH related code was implemented in the cli part of the rust app.

Describe the solution you'd like
A great step would be for the pyckel wrapper to honor the NICKEL_IMPORT_PATH environment variable.

And as a great bonus we could add an import optional argument for the pyckel.run function to be able to specify the import directory at runtime.

[yannham]

This should be pretty straightforward to implement, as pyckel manipulates a Program object that has an add_import_paths method taking a list of paths. I'm wondering how we should expose this on the Python side; maybe with an optional parameter?

I would be inclined to keep the python wrapper simple and avoid surprises by being too smart, such as automatically and silently honoring NICKEL_IMPORT_PATH. It's not obvious that this is a good default, depending on the use-case, so I would rather provide the knob on the run function and let the Python caller decided where to take those import paths from - potentially from NICKEL_IMPORT_PATH if they want to, but not necessarily.

[Dorsug]

Yes, an optional parameter is definitely the way to go for the python side, maybe named import_paths to stay consistent with the rust api.

Okay, it makes sense why the automatic env variable isn’t the right fit.