html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/pull/7051#issuecomment-1252964437,https://api.github.com/repos/pydata/xarray/issues/7051,1252964437,IC_kwDOAMm_X85KrrhV,5635139,2022-09-20T22:06:53Z,2022-09-20T22:06:53Z,MEMBER,"> Nothing wrong with None, it is just pythons default.
> 
> The intention of `replace_none=False` was to leave None as None, which is important for some low level functions as they might be optimized (like numpy sum, which sums over all axes for None).

Not relevant to this PR but for background — it used to be that `da.groupby()` defaulted to `None`, and reduced all dimensions — now for a couple of years we require `...`.

But still `da.sum()` is equivalent to `da.sum(...)`, which is arguably a bit incongruent with `da.sum('a')` reducing _fewer_ dimensions than `da.sum(['a','b'])`. But would be quite hard to change now.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1377097243
https://github.com/pydata/xarray/pull/7051#issuecomment-1252829551,https://api.github.com/repos/pydata/xarray/issues/7051,1252829551,IC_kwDOAMm_X85KrKlv,5635139,2022-09-20T19:47:20Z,2022-09-20T19:47:20Z,MEMBER,"> I always thought that these two methods are incompatible. But I guess ... Is synonym for None (= all dims) and if ... Appears in an iterable, it just means replace it with all leftover dims.

Yes! `...` is the better synonym — `None` is somewhat an artifact of history. So +1 for `replace_none`, which maybe we can gradually turn to `False` by default over time.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1377097243