If the file is empty (or contains no variables matching any filtering done by the backend), use a different error message indicating that, rather than suggesting that the file has too many variables for this function.
I feel like the new message could be longer, but there's not really a way to fix "no data" in python, unless the writing process decided to add everything to the global coordinates attribute or something.
[ ] User visible changes (including notable bug fixes) are documented in whats-new.rst
If the file is empty (or contains no variables matching any filtering done by the backend), use a different error message indicating that, rather than suggesting that the file has too many variables for this function.
I feel like the new message could be longer, but there's not really a way to fix "no data" in python, unless the writing process decided to add everything to the global
coordinatesattribute or something.whats-new.rst