GH1419 Allow Series and Index for other in Index.where(..., other)

[loicdiridollou]

• Closes Index.where(..., other) should support other with more than array-like #1419
• Tests added: Please use assert_type() to assert the type of any return value

[cmp0xff]

From the description in #1419, it seems the following tests are yet to be added:

• When the base instance is not of DatetimeIndex but just of a normal Index, .where also works with the changes
• other being a Series

Please make the tests complete. Thanks!

[cmp0xff]

pd.date_range already gives a DatetimeIndex at run time. You can do

Suggested change

	datetime_index = pd.DatetimeIndex(
	pd.date_range(start="2025-01-01", freq="h", periods=48)
	)
	datetime_index = pd.date_range(start="2025-01-01", freq="h", periods=48)

unless you need to cast (which can be fixed separately)

[loicdiridollou]

Converting to draft until response from pandas team.