diff --git a/registrasion/controllers/cart.py b/registrasion/controllers/cart.py
index f23de385a56cf1b190649c2d591ebb503da2ad07..95a2b92173ea5afc7a149fac60031a922fcd6656 100644
--- a/registrasion/controllers/cart.py
+++ b/registrasion/controllers/cart.py
@@ -6,7 +6,7 @@ import itertools
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.exceptions import ValidationError
 from django.db import transaction
-from django.db.models import Max, Sum
+from django.db.models import Max
 from django.utils import timezone
 
 from registrasion import models as rego
@@ -71,7 +71,6 @@ class CartController(object):
         self.cart.revision += 1
         self.cart.save()
 
-
     @transaction.atomic
     def set_quantities(self, product_quantities):
         ''' Sets the quantities on each of the products on each of the
@@ -194,8 +193,6 @@ class CartController(object):
         ''' Determines whether the status of the current cart is valid;
         this is normally called before generating or paying an invoice '''
 
-        is_reserved = self.cart in rego.Cart.reserved_carts()
-
         # TODO: validate vouchers
 
         items = rego.ProductItem.objects.filter(cart=self.cart)
diff --git a/registrasion/controllers/category.py b/registrasion/controllers/category.py
index 7f244263890e816aaa7249d78a97431d76f986f0..9ab9dd3be9bb44b2f3ca36eed272cda12db4cc46 100644
--- a/registrasion/controllers/category.py
+++ b/registrasion/controllers/category.py
@@ -53,10 +53,4 @@ class CategoryController(object):
         )
 
         cat_count = items.aggregate(Sum("quantity"))["quantity__sum"] or 0
-        
-        cat_limit = self.category.limit_per_user
-
-        if cat_limit is None:
-            return 999999  # We should probably work on this.
-        else:
-            return cat_limit - cat_count
+        cat_limit - cat_count
diff --git a/registrasion/controllers/conditions.py b/registrasion/controllers/conditions.py
index 731b7edce9ebad6c2898721d0fde16df98c94962..9a0b26df1360d6ad534a06efeebb1547813f16f6 100644
--- a/registrasion/controllers/conditions.py
+++ b/registrasion/controllers/conditions.py
@@ -3,7 +3,6 @@ import itertools
 from collections import defaultdict
 from collections import namedtuple
 
-from django.db.models import Q
 from django.db.models import Sum
 from django.utils import timezone
 
@@ -64,8 +63,8 @@ class ConditionController(object):
                              "product_quantities")
         elif products is None:
             products = set(i[0] for i in product_quantities)
-            quantities = dict( (product, quantity)
-                for product, quantity in product_quantities )
+            quantities = dict((product, quantity)
+                              for product, quantity in product_quantities)
         elif product_quantities is None:
             products = set(products)
             quantities = {}
@@ -84,7 +83,6 @@ class ConditionController(object):
         # if there are no mandatory conditions
         non_mandatory = defaultdict(lambda: False)
 
-        remainders = []
         for condition in all_conditions:
             cond = cls.for_condition(condition)
             remainder = cond.user_quantity_remaining(user)
@@ -233,6 +231,7 @@ class TimeOrStockLimitConditionController(ConditionController):
 
         return self.ceiling.limit - count
 
+
 class TimeOrStockLimitEnablingConditionController(
         TimeOrStockLimitConditionController):
 
diff --git a/registrasion/controllers/product.py b/registrasion/controllers/product.py
index 349d01d77769b4af0f3f9c322ee43d9ea58a2ea7..d25a79bbf361874d6883c46d13e4882e1ff2975c 100644
--- a/registrasion/controllers/product.py
+++ b/registrasion/controllers/product.py
@@ -1,6 +1,5 @@
 import itertools
 
-from django.db.models import Q
 from django.db.models import Sum
 from registrasion import models as rego
 
@@ -33,7 +32,9 @@ class ProductController(object):
         passed_limits = set(
             product
             for product in all_products
-            if CategoryController(product.category).user_quantity_remaining(user) > 0
+            if CategoryController(product.category).user_quantity_remaining(
+                user
+            ) > 0
             if cls(product).user_quantity_remaining(user) > 0
         )
 
diff --git a/registrasion/tests/cart_controller_helper.py b/registrasion/tests/cart_controller_helper.py
index 9176f2c8b1eee0628b2714b6dd2c17230fe81919..0578229755a93ea39e49b76ed6e8f75fe1477dfd 100644
--- a/registrasion/tests/cart_controller_helper.py
+++ b/registrasion/tests/cart_controller_helper.py
@@ -3,6 +3,7 @@ from registrasion import models as rego
 
 from django.core.exceptions import ObjectDoesNotExist
 
+
 class TestingCartController(CartController):
 
     def set_quantity(self, product, quantity, batched=False):
diff --git a/registrasion/tests/test_cart.py b/registrasion/tests/test_cart.py
index 45c18ef0215a685ae8405f198d1771b54c7184c7..1de72bc90c4c923ebb4e5c59fd1a3908e56b64f5 100644
--- a/registrasion/tests/test_cart.py
+++ b/registrasion/tests/test_cart.py
@@ -126,7 +126,6 @@ class RegistrationCartTestCase(SetTimeMixin, TestCase):
             quantity=10,
         ).save()
 
-
     @classmethod
     def new_voucher(self, code="VOUCHER", limit=1):
         voucher = rego.Voucher.objects.create(
diff --git a/registrasion/views.py b/registrasion/views.py
index f7e876941bc223d5edf80ad83c5242e4b74c8673..192f401d2fa0c63c1abc207ca2c972dfb7038697 100644
--- a/registrasion/views.py
+++ b/registrasion/views.py
@@ -14,7 +14,6 @@ from django.contrib.auth.decorators import login_required
 from django.contrib import messages
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.exceptions import ValidationError
-from django.db import transaction
 from django.http import Http404
 from django.shortcuts import redirect
 from django.shortcuts import render