Generate rgbas array in mobject

[GoThrones]

Overview: What does this pull request change?

This PR improves the docstring of the method: generate_rgbas_array in VMobject class. Also improves names of some of the variables in that method.

Reviewer Checklist

• The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• If applicable: newly added functions and classes are tested

[chopan050]

Thanks for your contribution! It's nice to have a more descriptive docstring and variable names.

I left some change requests:

[chopan050]

Can you please also fix the parameter typehints? color can be an iterable of any ParsableManimColors, not strictly ManimColors. opacity can also be None, given the code below. Technically, both iterables could also contain None values, but I don't think it's strictly necessary to include that last thing in the typehint...

Suggested change

	color: ParsableManimColor | Iterable[ManimColor] | None,
	opacity: float | Iterable[float],
	color: ParsableManimColor | Iterable[ParsableManimColor] | None,
	opacity: float | Iterable[float] | None,

[GoThrones]

Thanks for your suggestions. I've rectified the code to reflect those changes.

[chopan050]

There are some conventions which, admittedly, many of our current docstrings do not follow, so it would be nice to start enforcing them when improving the documentation. According to PEP 257:

The docstring is a phrase ending in a period. It prescribes the function or method’s effect as a command (“Do this”, “Return that”), not as a description; e.g. don’t write “Returns the pathname …”.

Suggested change

	"""Returns a 2D array of shape (N,4) where N is the number of colors in the list
	"""Return a 2D array of shape (N,4) where N is the number of colors in the list

[GoThrones]

I was aware of that convention. However, I must admit that whenever I see a new function/method, I question: What does this function do?
And the obvious way that i see the answer forming is: """This method/function returns...
or simply: """Returns... """

I have never found it intuitive to read the docstring that start like this: """Return this, or do that. """

Many of the functions/methods in manimce sourcecode, in many other files, already has the style: """Returns... """ or """Gets... """. So, maybe I'm not alone in thinking that it's better to read a function's/method's docstring as: """Returns... """ instead of """Return...".

Also, I'm wondering that is it really necessary or even desirable to follow this particular convention prescribed by PEP 257 ? And if yes, then to what end ?

[chopan050]

Notice that, according to the NumPy style guide which we want to follow, each parameter name must start at the same indentation level as the Parameters title, and the description of each parameter must start in a new line and with one more indentation level. Instead of:

Parameters
----------
    parameter1: Description 1
    parameter2: Description 2

it should be:

Parameters
----------
parameter1
    Description 1
parameter2
    Description 2

By formatting the docstring correctly, we can automatically generate correct documentation for the method. See the documentation for VMobject.generate_rgbas_array() which was automatically generated for this PR after you made it. Currently, the Parameters and Returns sections are duplicated because the Parameters section could not be parsed correctly.

Notice that the NumPy style guide mentions adding the typehint next to each parameter name in the docstring. However, we're not doing that in the docstring: it is enough with typehinting the parameters in the function declaration, and our documentation process captures those typehints and adds them into the Parameters section anyways.

Suggested change

	Parameters
	----------
	color: Can be a single color, or a tuple/list of colors, or any of the ParsableManimColor.
	opacity: Can either be a float, or a tuple/list or any iterable of floats.
	Parameters
	----------
	color
	A single color, an iterable of multiple colors, or `None` (which is replaced
	with `BLACK`).
	opacity
	The opacity of a color as a number between 0.0 and 1.0, an iterable of multiple
	color opacities, or `None` (which is replaced with 0.0).

[GoThrones]

Thanks for your suggestions.
I've rectified the code in accordance with your suggestion, with some minor alterations.