DEPR: DatetimeIndex.offset

[jschendel]

DatetimeIndex.offset and DatimeIndex.freq refer to the same thing, and are used interchangeably throughout the code for DatetimeIndex:

pandas/pandas/core/indexes/datetimes.py

Lines 1729 to 1732 in 4a34497

	@property
	def freq(self):
	"""get/set the frequency of the Index"""
	return self.offset

Is there a reason for having both?

TimedeltaIndex and PeriodIndex only have freq, so it seems like we could keep freq for consistency, deprecate DatetimeIndex.offset, and modify the DatetimeIndex code to only use freq.

[jorisvandenbossche]

+1 to deprecate .offset (will probably need some rework, as now it is freq that is calling offset which is used internally it seems)

[jreback]

note we deprecated Timestamp.offset in #13593

[subhrm]

If no one has started working on this, I would like to take this up.

[jschendel]

@subhrm : I've started some work on this as a precursor to fixes for #20678

[subhrm]

@jschendel Okay.