API: make '+' and '-' for Index either do numeric operations of raise TypeError (instead of setops) · Issue #8226 · pandas-dev/pandas (original) (raw)

see comments at the end of #8184

so this type of syntax

index1 + index2
would be replaced by
index1.union(index2)

and

index1 - index2
by
index1.diff(index2)

Their is some internal code to fix but not a lot.

This would go a long ways toward simplifying the user API for index ops. I think.