diff --git a/dibbler/lib/helpers.py b/dibbler/lib/helpers.py
index cacf827..30926a3 100644
--- a/dibbler/lib/helpers.py
+++ b/dibbler/lib/helpers.py
@@ -44,7 +44,7 @@ def search_product(string, session, find_hidden_products=True):
             .filter(
                 or_(
                     Product.bar_code == string,
-                    and_(Product.name == string, Product.hidden == False),
+                    and_(Product.name == string, Product.hidden is False),
                 )
             )
             .first()
@@ -68,7 +68,7 @@ def search_product(string, session, find_hidden_products=True):
             .filter(
                 or_(
                     Product.bar_code.ilike(f"%{string}%"),
-                    and_(Product.name.ilike(f"%{string}%"), Product.hidden == False),
+                    and_(Product.name.ilike(f"%{string}%"), Product.hidden is False),
                 )
             )
             .all()
@@ -103,14 +103,13 @@ def guess_data_type(string):
 
 def argmax(d, all=False, value=None):
     maxarg = None
-    maxargs = []
-    if value != None:
+    if value is not None:
         dd = d
         d = {}
         for key in list(dd.keys()):
             d[key] = value(dd[key])
     for key in list(d.keys()):
-        if maxarg == None or d[key] > d[maxarg]:
+        if maxarg is None or d[key] > d[maxarg]:
             maxarg = key
     if all:
         return [k for k in list(d.keys()) if d[k] == d[maxarg]]
diff --git a/dibbler/lib/statistikkHelpers.py b/dibbler/lib/statistikkHelpers.py
index e345230..80ea886 100644
--- a/dibbler/lib/statistikkHelpers.py
+++ b/dibbler/lib/statistikkHelpers.py
@@ -283,10 +283,8 @@ def buildDatabaseFromDb(inputType, inputProduct, inputUser):
     for transaction in transaction_list:
         if transaction.purchase:
             products = "¤".join([ent.product.name for ent in transaction.purchase.entries])
-            description = ""
         else:
             products = ""
-            description = transaction.description
         line = line_format % (
             "purchase",
             transaction.time,
diff --git a/dibbler/menus/__init__.py b/dibbler/menus/__init__.py
index 1adb076..a578490 100644
--- a/dibbler/menus/__init__.py
+++ b/dibbler/menus/__init__.py
@@ -1,3 +1,28 @@
+__all__ = [
+    "AddProductMenu",
+    "AddStockMenu",
+    "AddUserMenu",
+    "AdjustCreditMenu",
+    "AdjustStockMenu",
+    "BalanceMenu",
+    "BuyMenu",
+    "CleanupStockMenu",
+    "EditProductMenu",
+    "EditUserMenu",
+    "FAQMenu",
+    "LoggedStatisticsMenu",
+    "MainMenu",
+    "Menu",
+    "PrintLabelMenu",
+    "ProductListMenu",
+    "ProductPopularityMenu",
+    "ProductRevenueMenu",
+    "ProductSearchMenu",
+    "ShowUserMenu",
+    "TransferMenu",
+    "UserListMenu",
+]
+
 from .addstock import AddStockMenu
 from .buymenu import BuyMenu
 from .editing import (
diff --git a/dibbler/models/Purchase.py b/dibbler/models/Purchase.py
index aa1902e..b725f96 100644
--- a/dibbler/models/Purchase.py
+++ b/dibbler/models/Purchase.py
@@ -5,10 +5,8 @@ from datetime import datetime
 import math
 
 from sqlalchemy import (
-    Boolean,
     DateTime,
     Integer,
-    String,
 )
 from sqlalchemy.orm import (
     Mapped,
diff --git a/dibbler/models/__init__.py b/dibbler/models/__init__.py
index 9fbd1da..20999e9 100644
--- a/dibbler/models/__init__.py
+++ b/dibbler/models/__init__.py
@@ -1,3 +1,13 @@
+__all__ = [
+    'Base',
+    'Product',
+    'Purchase',
+    'PurchaseEntry',
+    'Transaction',
+    'User',
+    'UserProducts',
+]
+
 from .Base import Base
 from .Product import Product
 from .Purchase import Purchase