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/5607#issuecomment-881969320,https://api.github.com/repos/pydata/xarray/issues/5607,881969320,IC_kwDOAMm_X840kcio,1217238,2021-07-17T22:39:02Z,2021-07-17T22:39:02Z,MEMBER,"> @shoyer That would either not work, or be needlessly expensive, I think. The message generation might be expensive (e.g. if I want a sum or mean of the differences). With a call back it only happens if it is needed. With a pre-computed message it would be computed every time.. Correct me if I'm wrong.

I'm mostly thinking of the precedent from the standard library's unittest library and numpy.testing.

It does indeed add a bit of expense to add a custom message, but I guess it's generally acceptable for testing? If not, I would kind of expect to add support for callables in those libraries first.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,945226829
https://github.com/pydata/xarray/pull/5607#issuecomment-881556130,https://api.github.com/repos/pydata/xarray/issues/5607,881556130,IC_kwDOAMm_X840i3qi,1217238,2021-07-16T16:04:42Z,2021-07-16T16:04:42Z,MEMBER,I think the more standard way to handle this is to add an argument for supplying an auxiliary `err_msg` rather than a callback. But this would definitely be welcome functionality!,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,945226829