types are referenced from too deep

[mattijn]

Given the following spec:

import altair as alt
from vega_datasets import data

cars = data.cars()
alt.Chart(cars).mark_point().encode(
    x='Horsepower',
    y='Miles_per_Gallon',
    color='Origin',
)

I created a screenshot of the documentation of alt.Chart (the one that appears when using shift+tab):

It gives type hints for the available options. That is nice! I underlined just one random, which is currently referred as

altair.vegalite.v5.schema.core.Generator

But almost all of these type hints are also available from the altair root, like:

alt.Generator

Can we change this reference for these type hints? This will make these information panels with documentation and type hints easier to understand.

As was discussed here: #3333 (comment).

Side note: some of these type hints are not available from the altair root, such as:

altair.utils.data.SupportsGeoInterface

Which is not available under

alt.SupportsGeoInterface

(edit: of which I think it should be available from the root)

[binste]

Thanks for writing this down! Unfortunately, this might not be possible. A type is defined in one place and at least VS Code and Jupyter Lab use the location of the actual definition of the type which is also consistent with Python's type function. I did not find a way to change this.

Here's an example. We define class A in one file:

first_module.py:

class A:
    pass

import it in another:

another_module.py:

from first_module import A

And then from there import it in a notebook and use it as a type hint:

It shows as first_module.A although we imported it from another_module.

Now that Altair no longer supports different Vega-Lite and even Vega versions, I'd be in favour of simplifying the folder structure for the next major release when it comes. This would help with version control (all files in new v5, v6, ... folders show up as "new" which makes it difficult to compare against older versions) and also with type hints. It could simply be altair.schema.core.Generator.

[mattijn]

Hm that is unfortunate. Yes, I agree that simplifying the folder structure with a major release is good alternative solution to improve this.
As the current folder structure has become very visible with the type hints..

[binste]

I've opened #3337 to track the idea of simplifying the package structure.