Ability to configure log levels from the command line.

Author: dames

relational_data_loader_project/BatchDataLoader.py

@@ -43,7 +43,7 @@ def import_batch(self, source_engine, target_engine, target_table_configuration,
         batch_tracker.extract_completed_successfully(len(data_frame))
 
         if len(data_frame) == 0:
-            self.logger.info("There are no rows to import, returning False")
+            self.logger.debug("There are no rows to import, returning -1")
             batch_tracker.load_skipped_due_to_zero_rows()
             return -1
 

relational_data_loader_project/__main__.py

@@ -3,25 +3,41 @@
 from sqlalchemy import create_engine
 import argparse
 
+_LOG_LEVEL_STRINGS = ['CRITICAL', 'ERROR', 'WARNING', 'INFO', 'DEBUG']
+
 
 def main(args):
-    configure_logging()
+
+    configure_logging(args['log_level'])
     source_engine = create_engine(args['source-engine'])
     destination_engine = create_engine(args['destination-engine'])
 
     data_load_manager = DataLoadManager(args['configuration-folder'])
     data_load_manager.start_import(source_engine, destination_engine, True)
 
 
-def configure_logging():
+def configure_logging(log_level):
     formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
     log = logging.getLogger()
     console_stream_handler = logging.StreamHandler()
     console_stream_handler.setFormatter(formatter)
     log.addHandler(console_stream_handler)
-    log.setLevel(logging.INFO)
+    log.setLevel(log_level)
     return
 
+
+def _log_level_string_to_int(log_level_string):
+    if not log_level_string in _LOG_LEVEL_STRINGS:
+        message = 'invalid choice: {0} (choose from {1})'.format(log_level_string, _LOG_LEVEL_STRINGS)
+        raise argparse.ArgumentTypeError(message)
+
+    log_level_int = getattr(logging, log_level_string, logging.INFO)
+    # check the logging log_level_choices have not changed from our expected values
+    assert isinstance(log_level_int, int)
+
+    return log_level_int
+
+
 def get_arguments():
     parser = argparse.ArgumentParser(description='Relational Data Loader')
 
@@ -32,14 +48,17 @@ def get_arguments():
                         help='The destination engine. Eg: postgresql+psycopg2://postgres:xxxx@localhost/dest_dw')
 
     parser.add_argument('configuration-folder', metavar='configuration-folder',
-                        help='The configration folder. Eg C:\\_dev\\oscars-misc\\el-pipeline-spike\\configuraton\\')
+                        help='The configuration folder. Eg C:\\_dev\\oscars-misc\\el-pipeline-spike\\configuraton\\')
+
+    parser.add_argument('--log-level',
+                        default='INFO',
+                        type=_log_level_string_to_int,
+                        nargs='?',
+                        help='Set the logging output level. {0}'.format(_LOG_LEVEL_STRINGS))
 
     return vars(parser.parse_args())
 
 
 if __name__ == "__main__":
     args = get_arguments()
     main(args)
-
-
-