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/issues/3205#issuecomment-520287442,https://api.github.com/repos/pydata/xarray/issues/3205,520287442,MDEyOklzc3VlQ29tbWVudDUyMDI4NzQ0Mg==,1217238,2019-08-12T03:00:49Z,2019-08-12T03:00:49Z,MEMBER,"I'm leaning towards (1), unfortunately. Xarray's data model doesn't keep around the `DataArray` objects that are part of a `Dataset`, only `Variable` objects. So even if we cached `DataArray` objects on a `Dataset`, they would get lost as soon as you do any sort of more complex computation or data manipulation.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,479420466 https://github.com/pydata/xarray/issues/3205#issuecomment-520274338,https://api.github.com/repos/pydata/xarray/issues/3205,520274338,MDEyOklzc3VlQ29tbWVudDUyMDI3NDMzOA==,1217238,2019-08-12T00:33:13Z,2019-08-12T00:33:13Z,MEMBER,"> My guess is that `Dataset.__getitem__` is recreating the `DataArray` every time from the underlying `Variable` object which means `ds['a'] is not ds['a']`? Yes, I believe this is the case.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,479420466