netcdf_concat.py

    # for each file in the list we concatenate it to the base dataset
    output_file_name = root_file_name + '.v7_plus_first_guess.nc'
    with xarray.open_dataset(base_file_name) as output_dataset:
        
        # loop over the first guess files, concatenating (appending?) each to the base (output) dataset
        for first_guess_file in first_guess_files:
    
            # open the first guess dataset, concatenate it with the base (output) dataset 
            with xarray.open_dataset(first_guess_file, decode_times=False) as first_guess_dataset:
                output_dataset = xarray.concat([output_dataset.precip[:, :, :], first_guess_dataset.p[0]], dim='time, lat, lon')

        # write the base (output) dataset as a new NetCDF file
        output_dataset.to_netcdf(output_file_name, encoding = {'precip': {'_FillValue': np.nan, 'dtype': 'float32'}})