Replace getters and setters (where possible) by property or direct access

[PgBiel]

We should replace getters and setters, which are an antipattern in Python (as exposed on #122 (comment)). Most of them can be replaced either by:

1. The use of @property (which allows custom code to run when access is attempted or an assignment is done);
2. Direct access to the attribute (i.e. just delete the get and set functions where they don't do anything at all besides just getting or setting).

As I exposed in #122 (comment), rather than having a set function for each attribute, we should (also) implement a general set function for dataclasses, which allows us to set multiple attributes at a time (and also to animate such setting), like so:

mobj.set(x=5, y=6, z_index=50, ...)

Setter functions which require more than one parameter could be kept anyways, and then simply invoked by .set when required.

Suggestions? Ideas?

Relevant PRs and comments (if there are more, please tell me or just edit this post): #122 (comment), #122 (comment), #116, #114

[leotrs]

Can we have here a clear distinction/guidelines for when to use just an attribute and when to use a property? Also, should we do this after the dataclass/attr refactor? So as to not duplicate efforts...

[PgBiel]

Can we have here a clear distinction/guidelines for when to use just an attribute and when to use a property?

In general, you will only use a property when the action of getting or setting requires extra code other than simply retrieving an attribute.

Also, should we do this after the dataclass/attr refactor? So as to not duplicate efforts...

Also, yes, I'm just not sure about whether we should do it during the refactor or after, but perhaps we can do it after

[leotrs]

This issue was left open only because it depended on the implementing of attrs/dataclasses. But latest developments in #7 sound like that will never happen.

Besides, I have already gotten rid of some get/set methods in some classes.

[PgBiel]

@leotrs but are we going to implement it? If so, it should be left open, no?