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/3770#issuecomment-587130487,https://api.github.com/repos/pydata/xarray/issues/3770,587130487,MDEyOklzc3VlQ29tbWVudDU4NzEzMDQ4Nw==,14808389,2020-02-17T19:29:27Z,2020-02-17T19:29:27Z,MEMBER,"The [docs](https://docs.python.org/3/library/stdtypes.html#truth-value-testing) state that the builtin `bool` returns `True` for all objects unless `__bool__` is defined or `__len__` returns `0` (function objects don't define either so they use the fallback). I'm not sure why, but I suspect it is the way it is to make ```python if obj: ... ``` equivalent to ```python if obj is not None: ... ``` That said I really like the callable support of pandas (e.g. `Series.where`), so maybe we should add that too?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,565626748