DEPR: .take(..., is_copy=True); rename is_copy -> copy

[jreback]

this is more in-line with our other signatures. ideally would do this for 0.25

[jorisvandenbossche]

Or simply deprecate this without replacement? A take operation is in principle always a copy

[jreback]

you can try to deprecate it entirely if that works

[jorisvandenbossche]

So the special case for "no copy" is when the result is exactly the same as the caller. Personally, I don't think we need to provide this special case (if the user cares about the performance in that corner case, they can do the check themselves)

[chrisstpierre]

I opened a PR to deprecate it in 0.25.2. is_copy is supposed to be removed all-together in 1.0.0.

take always returns a copy

pandas/pandas/core/generic.py

Lines 3437 to 3439 in c4489cb

	new_data = self._data.take(
	indices, axis=self._get_block_manager_axis(axis), verify=True
	)

pandas/pandas/core/internals/managers.py

Lines 1394 to 1396 in c4489cb

	return self.reindex_indexer(
	new_axis=new_labels, indexer=indexer, axis=axis, allow_dups=True
	)

pandas/pandas/core/internals/managers.py

Lines 1222 to 1224 in c4489cb

	def reindex_indexer(
	self, new_axis, indexer, axis, fill_value=None, allow_dups=False, copy=True
	):

Copy is true by default.

[jorisvandenbossche]

@chrisstpierre can you open a new PR against master? (using the same branch, but not selecting the 0.25.x branch when opening the PR)
I looked at the commit you added, and that by itself looks good!

[chrisstpierre]

@jorisvandenbossche just did that.

But I still have .. deprecated:: 0.25.2.

Should it be 1.0.0 ?