CLN: .values -> ._values
> what logic do we we use to decide when to use which property?

The default should be ._values, as .values may be either lossy (dt64tz), involve an object-dtype cast (period, interval), or be surprising (until recently I forgot that Series[Sparse].values gives a SparseArray, not ndarray).

Both this and #32781 are aimed at usages where the two are equivalent.  This should make it easier to focus attention on usages where they are not equivalent, and double-check whether those are intentional or improveable. comments here: https://github.com/pandas-dev/pandas/pull/32781#issuecomment-600927742 Travis yellow is wrong; travis is green kk, no test covers this? > no test covers this?

not sure what you're referring to