get-airnow xarray error

[dwfncar]

melodies-monet get-airnow --start-date 20240521 --end-date 20240522

results in an xarray error

Fetching data with monetio ...
Aggregating AIRNOW files...
Building AIRNOW URLs...
Adding in Meta-data
Fetching data with monetio succeeded in 0.619 seconds
Forming xarray Dataset ...
Forming xarray Dataset failed in 0.00887 seconds
Error message: single positional indexer is out-of-bounds

[zmoon]

@dwfncar I suspect this means no data was found for the period at the time of your invocation. It works for me now. But the error message could certainly be improved for this situation. In the future, note that if you add the --debug flag you can see the full traceback.

[blychs]

@rschwant What is the task here? Is it improving the error message, as Zach mentioned?

[rschwant]

I'm not sure. I think this was resolved right @zmoon. I think David was looking for data that was not yet available as there is a delay for uploading the data to the amazon servers we use for downloading.

[zmoon]

We have yet to improve the error message. It's the .iloc[0] here that causes this error when there is no data for a requested period.

MELODIES-MONET/melodies_monet/_cli.py

Line 451 in b243d09

units = df[unit_cols][~df[unit_cols].isnull()].iloc[0].to_dict()

So, just need to check if it's empty and print an appropriate error message (and exit with rc 1) before attempting to create the units dict.

There's another confusing error you can get if you request when the files on S3 are in the midst of being updated/uploaded, Dask complaining about files not matching dtype/cols.