Try logging.

brmbar3/brmbar-gui-qt4.py

@@ -11,6 +11,17 @@ import brmbar
 
 import argparse
 
+import logging
+
+root = logging.getLogger()
+root.setLevel(logging.DEBUG)
+
+handler = logging.StreamHandler(sys.stdout)
+handler.setLevel(logging.DEBUG)
+formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
+handler.setFormatter(formatter)
+root.addHandler(handler)
+
 # User credit balance limit; sale will fail when balance is below this limit.
 LIMIT_BALANCE = -200
 # When below this credit balance, an alert hook script (see below) is run.

brmbar3/brmbar/Account.py

@@ -1,4 +1,6 @@
 from .Currency import Currency
+import logging
+logger = logging.getLogger(__name__)
 
 class Account:
     """ BrmBar Account
@@ -14,6 +16,7 @@ class Account:
 
     @classmethod
     def load_by_barcode(cls, db, barcode):
+        logger.debug("load_by_barcode: %s", barcode)
         res = db.execute_and_fetch("SELECT account FROM barcodes WHERE barcode = %s", [barcode])
         if res is None:
             return None