Error cfgrib.to_grib convert netcdf to grib

[taoansf]

Hello,

I'm looking for a solution to write a grib file from a netcdf data using this code

#! /usr/bin/env python
import xarray as xa
import cfgrib
ds = xa.open_dataset('2015-01-15.nc')
cfgrib.to_grib(ds,'2015-01-15.grb', grib_keys={'gridType':'regular_ll'})

However python give me this error mensage

File "C:\Users\Usuario\Miniconda3\lib\site-packages\cfgrib\bindings.py", line 442, in portable_handle_new_from_samples
sample_path = os.path.join(samples_folder, samplename + b'.tmpl')
TypeError: must be str, not bytes

This is my input file, from SST-MUR data

2015-01-15.zip

I will appreciate any help with this problem.

With best regards,

Taoan

[alexamici]

@taoansf ouch! This is a typical brown-paper-bag bug. It appears only on Windows. Sorry!

I fixed it in the stable/0.9,7.x branch, I'll try to push a release ASAP. Thanks!

[taoansf]

Thank you @alexamici you are right, that error does not occur on my linux environment.

However, when I try to load the grib output with this code it does not work
#! /usr/bin/env python
import xarray as xa
import cfgrib
ds1 = xa.open_dataset('2015-01-15.nc')
cfgrib.to_grib(ds1,'2015-01-15.grb', grib_keys={'gridType':'regular_ll'})
ds2=xa.open_dataset('2015-01-15.grb', engine='cfgrib')

Do you have some idea how to solve this?

With best regards,

Taoan

[taoansf]

This is the error message

My grib output
2015-01-15-grib.zip

[alexamici]

The problem it that in order to save arbitrary netCDF files to GRIB with cfgrib you must specify all the grib_keys that are not automatically computed. At the moment very few keys are computed and you need to set almost all the values as you would do with ecCodes.

Saving a to grib a GRIB file opened with cfgrib works more often because the dataset keeps the GRIB keys of the original file, but if you start from a netCDF you need to do the work manually and you need to know the GRIB data format.

[taoansf]

Thank you @alexamici, your explanation was very precise.
I will check eccodes documentation about the grib_keys to format my netcdf input.

With best regards,

Taoan