issue_comments: 1204310218

Yes, it is reasonable to always seek(0) or to copy the file. I am not certain why/where xarray is caching the open file, though - I would have thought that a new file instance is made for each open_dataset(). I am not certain whether seeking/reading from the same file in multiple places might have unforeseen consequences, such as when doing open_dataset in multiple threads.

I am mildly against subclassing from RawIOBase, since some file-likes might choose to implement text mode right in the class (as opposed to a text wrapper layered on top). Pretty surprised that it doesn't have read()/write(), though, since all the derived classes do.