add notes only if present

metadata_tools/importxls/dish_xls_exporter.py

@@ -97,7 +97,10 @@ class DishXlsExporter:
 
                     data_type_info = self.process_data_types(get_value_list_from_row(sheet, 6))
                     datadec_dict["data_types"].extend(data_type_info[0])
-                    datadec_dict["data_type_notes"] = datadec_dict["data_type_notes"] +" "+ data_type_info[1]+ " Notes on samples: " + sheet[10, 1]
+                    if data_type_info[1]:
+                        datadec_dict["data_type_notes"] += " " + data_type_info[1]
+                    if sheet[10, 1]:
+                        datadec_dict["data_type_notes"] += " Notes on samples: " + sheet[10, 1]
 
                     #if it involves samples add this as a datatype
                     if process_yes_no_answer(sheet[9, 1]):