Add an alias `ImportFrom.module` and fix other inconsistencies with the ast module

[tristanlatr]

I was expecting my current visitors simply based on the ast module to be working seemlessly with astroid trees, but it turns out some attributes names are not matching the ones in the standrd library.

Current behavior

When trying to get node.module on a fresh astroid.ImportFrom:

AttributeError: 'ImportFrom' object has no attribute 'module'

Expected behavior

ImportFrom.module would be an alias to ImportFrom.modname to match standard library names such that less effort is needed to adopt astroid.

Astroid version: 2.9.3

[DanielNoord]

Commit that last changed this attribute name is: c3a35e5

I'm not sure why module wasn't chosen.

[tristanlatr]

Other inconsistencies:

ClassDef.decorators.nodes -> ClassDef.decorator_list
Attribute.attrname -> Attribute.name
Attribute.expr -> Attribute.value
Name.name -> Name.id
UnaryOp.op:str -> UnaryOp.op:enum members maybe that should extend str to keep compatibility.

[Pierre-Sassoulas]

I think we should introduce aliases to match what the ast does (without changing the API we have, only adding aliases), what do you think @hippo91 ?

[cdce8p]

I think we should introduce aliases to match what the ast does (without changing the API we have, only adding aliases)

That will get confusing quickly. These inconsistencies are just something that accumulates with time. It isn't too difficult to live with. Compared to aliases. Try understanding code that uses both simultaneously. I would be against it. Like I explained elsewhere astroid isn't designed to be a drop-in replacement for the ast module.

[tristanlatr]

I think the readme should be changed, it currently says:

It [astroid] provides a compatible representation which comes from the _ast module.

Maybe also I'm misunderstanding the sentence and the compatibility we're talking about here is about different python versions, it should probably be rephrased if that's the intended meaning.

[DanielNoord]

I think an update to the readme would be helpful. Would you want to provide a PR for that? I think you probably have the most experience about what astroid does and does not have in common with ast.