gh-501: change imports to be directly from glass

[paddyroddy]

Description

Changes the code throughout to use import glass rather than from glass import where possible. This is possible via the __all__ statements in __init__.py. I have also done this for glass.grf.

Closes: #501

Changelog entry

Checks

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• Is your code passing tests?
• Have you added additional tests (if required)?
• Have you modified/extended the documentation (if required)?
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[paddyroddy]

This one has to remain from glass.grf syntax as otherwise we run into a circular import

[paddyroddy]

This was incorrect before

[Saransh-cpp]

Thanks, looks good to me!

[ntessore]

Thanks for doing all those changes!

I hadn't really thought about use of glass from inside the library itself, I was only considering tests and examples as "uses" of glass. Do you then prefer to use the glass namespace everywhere, even in library code itself? I have no opinion either way.

[paddyroddy]

Do you then prefer to use the glass namespace everywhere, even in library code itself? I have no opinion either way.

I don't really mind. I think there are benefits of both.

The way I've done it means that you are using the library as an external user would. So in a sense it's another check that __all__ etc. is working.

On the other hand, having full path imports means that at a glance you know exactly where something is coming from. This is why I in general prefer import <x>; <x>.<y>, rather than from <x> import <y>, as at a glance I wouldn't know where <y> has come from.

@Saransh-cpp do you have any views of which style we should use here?

[Saransh-cpp]

I like import <x>; <x>.<y> as well for the same reasons.

Also, all the popular conventions in the Python ecosystem are always of the form import <x>; <x>.<y> -

numpy.array
plt.plot
pd.DataFrame
...

[ntessore]

Ok, then let's always use glass. even in GLASS itself. I guess that doesn't cause any more circular import grief than the from ... import ... methods, since latter also imports glass first. LGTM!!