EUCLIDPCR-1914 Raise an exception.

Author: Jorge Fernandez Hernandez

astroquery/esa/euclid/core.py

@@ -1231,8 +1231,7 @@ def get_spectrum(self, *, source_id, schema='sedm', retrieval_type="ALL", output
         output_file_full_path, output_dir = self.__set_dirs(output_file=output_file, observation_id=fits_file)
 
         if os.listdir(output_dir):
-            log.error(f'The directory is not empty: {output_dir}')
-            return
+            raise Exception(f'The directory is not empty: {output_dir}')
 
         try:
             self.__eucliddata.load_data(params_dict=params_dict, output_file=output_file_full_path, verbose=verbose)