API: deprecate combineAdd and combineMult methods?

[jorisvandenbossche]

On a DataFrame, we have the combineAdd and combineMult methods:

• they are a redundant, as they are defined as self.add(other, fill_value=0.) and self.mul(other, fill_value=1.) (that is the actual implementation), which is also just cleaner to use IMHO.
• they have awkward (and non-pep8) names
• I assume they are not used a lot (I found 3 relevant references on StackOverflow for combineAdd (SO1, SO2 and SO2, which is more than I expected), and none for combineMult

Therefore, I was thinking we could maybe deprecate these (as kind of clean-up)?

[jreback]

yeh they have a 'deprecated stuff' comment, but were not actually deprecated, sigh :( so let's deprecate and remove in next version.

[jorisvandenbossche]

yeh they have a 'deprecated stuff' comment,

Ah, yes, you mean in the codebase (as in the docstring nothing is said about that ..)

Will do a PR in a few days if no one complains

[TomAugspurger]

+1 for deprecation.

[jreback]

yes I think these are pretty old methods, and superfluous with .add,.mult. Let's just actually deprecate them.