import xarray as xr, salem

cntry_name = 'Thailand'
shdf = salem.read_shapefile(salem.get_demo_file('world_borders.shp'))
shdf = shdf[ shdf['CNTRY_NAME']==cntry_name ]

ofile = f'chirps.p05.{cntry_name}.nc'
data_name = 'precip'

# mask the grids outside of the country
da = xr.open_dataset(ofile)[data_name].salem.roi(shape=shdf)

# save the masked data to the ofile
da.to_dataset().to_netcdf(ofile.replace(cntry_name, cntry_name+'.masked'), unlimited_dims='time')