diff --git a/registrasion/controllers/invoice.py b/registrasion/controllers/invoice.py
index de401d31..fce09f8f 100644
--- a/registrasion/controllers/invoice.py
+++ b/registrasion/controllers/invoice.py
@@ -142,7 +142,6 @@ class InvoiceController(object):
 
         return False
 
-
     def _refresh(self):
         ''' Refreshes the underlying invoice and cart objects. '''
         self.invoice.refresh_from_db()
diff --git a/registrasion/tests/controller_helpers.py b/registrasion/tests/controller_helpers.py
index 476351dd..ad8661b6 100644
--- a/registrasion/tests/controller_helpers.py
+++ b/registrasion/tests/controller_helpers.py
@@ -3,7 +3,6 @@ from registrasion.controllers.invoice import InvoiceController
 from registrasion import models as rego
 
 from django.core.exceptions import ObjectDoesNotExist
-from django.core.exceptions import ValidationError
 
 
 class TestingCartController(CartController):
@@ -41,7 +40,7 @@ class TestingInvoiceController(InvoiceController):
         self.validate_allowed_to_pay()
 
         ''' Adds a payment '''
-        payment = rego.ManualPayment.objects.create(
+        rego.ManualPayment.objects.create(
             invoice=self.invoice,
             reference=reference,
             amount=amount,
diff --git a/registrasion/tests/test_discount.py b/registrasion/tests/test_discount.py
index e9105378..e84ca283 100644
--- a/registrasion/tests/test_discount.py
+++ b/registrasion/tests/test_discount.py
@@ -5,7 +5,6 @@ from decimal import Decimal
 from registrasion import models as rego
 from registrasion.controllers import discount
 from controller_helpers import TestingCartController
-from controller_helpers import TestingInvoiceController
 
 from test_cart import RegistrationCartTestCase
 
diff --git a/registrasion/tests/test_invoice.py b/registrasion/tests/test_invoice.py
index b121bfa1..7854680d 100644
--- a/registrasion/tests/test_invoice.py
+++ b/registrasion/tests/test_invoice.py
@@ -197,7 +197,7 @@ class InvoiceTestCase(RegistrationCartTestCase):
     def test_cannot_generate_blank_invoice(self):
         current_cart = TestingCartController.for_user(self.USER_1)
         with self.assertRaises(ValidationError):
-            invoice_1 = TestingInvoiceController.for_cart(current_cart.cart)
+            TestingInvoiceController.for_cart(current_cart.cart)
 
     def test_cannot_pay_implicitly_void_invoice(self):
         cart = TestingCartController.for_user(self.USER_1)
@@ -210,8 +210,6 @@ class InvoiceTestCase(RegistrationCartTestCase):
         with self.assertRaises(ValidationError):
             invoice.validate_allowed_to_pay()
 
-
-
     # TODO: test partially paid invoice cannot be void until payments
     # are refunded
 
diff --git a/registrasion/util.py b/registrasion/util.py
index fb97d1d5..3df54800 100644
--- a/registrasion/util.py
+++ b/registrasion/util.py
@@ -2,6 +2,7 @@ import string
 
 from django.utils.crypto import get_random_string
 
+
 def generate_access_code():
     ''' Generates an access code for users' payments as well as their
     fulfilment code for check-in.
diff --git a/registrasion/views.py b/registrasion/views.py
index 1b0fe646..f0795647 100644
--- a/registrasion/views.py
+++ b/registrasion/views.py
@@ -484,7 +484,7 @@ def invoice(request, invoice_id, access_code=None):
     if not current_invoice.can_view(
             user=request.user,
             access_code=access_code,
-        ):
+            ):
         raise Http404()
 
     data = {