diff --git a/lms/djangoapps/shoppingcart/migrations/0001_initial.py b/lms/djangoapps/shoppingcart/migrations/0001_initial.py
index 5209a2c6a6..fc79d98b49 100644
--- a/lms/djangoapps/shoppingcart/migrations/0001_initial.py
+++ b/lms/djangoapps/shoppingcart/migrations/0001_initial.py
@@ -1,11 +1,11 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
-from django.db import migrations, models
-import django.utils.timezone
 import django.db.models.deletion
-from django.conf import settings
+import django.utils.timezone
 import model_utils.fields
+from django.conf import settings
+from django.db import migrations, models
 from opaque_keys.edx.django.models import CourseKeyField
 
 
diff --git a/lms/djangoapps/shoppingcart/migrations/0002_auto_20151208_1034.py b/lms/djangoapps/shoppingcart/migrations/0002_auto_20151208_1034.py
index bb58cbfdc3..f32c3a720f 100644
--- a/lms/djangoapps/shoppingcart/migrations/0002_auto_20151208_1034.py
+++ b/lms/djangoapps/shoppingcart/migrations/0002_auto_20151208_1034.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import migrations, models
 
diff --git a/lms/djangoapps/shoppingcart/migrations/0003_auto_20151217_0958.py b/lms/djangoapps/shoppingcart/migrations/0003_auto_20151217_0958.py
index 3b78d0e508..6f1a7db3f4 100644
--- a/lms/djangoapps/shoppingcart/migrations/0003_auto_20151217_0958.py
+++ b/lms/djangoapps/shoppingcart/migrations/0003_auto_20151217_0958.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import migrations, models
 
diff --git a/lms/djangoapps/shoppingcart/migrations/0004_change_meta_options.py b/lms/djangoapps/shoppingcart/migrations/0004_change_meta_options.py
index 646b73a10a..743e12cc87 100644
--- a/lms/djangoapps/shoppingcart/migrations/0004_change_meta_options.py
+++ b/lms/djangoapps/shoppingcart/migrations/0004_change_meta_options.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.11.13 on 2018-05-14 20:37
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import migrations
 
diff --git a/lms/djangoapps/shoppingcart/processors/CyberSource2.py b/lms/djangoapps/shoppingcart/processors/CyberSource2.py
index 7157a8bce8..43462287ed 100644
--- a/lms/djangoapps/shoppingcart/processors/CyberSource2.py
+++ b/lms/djangoapps/shoppingcart/processors/CyberSource2.py
@@ -20,6 +20,8 @@ To enable this implementation, add the following Django settings:
 
 """
 
+from __future__ import absolute_import
+
 import binascii
 import hmac
 import json
@@ -209,7 +211,7 @@ def sign(params):
         dict: The same parameters dict, with a 'signature' key calculated from the other values.
 
     """
-    fields = u",".join(params.keys())
+    fields = u",".join(list(params.keys()))
     params['signed_field_names'] = fields
 
     signed_fields = params.get('signed_field_names', '').split(',')
diff --git a/lms/djangoapps/shoppingcart/processors/__init__.py b/lms/djangoapps/shoppingcart/processors/__init__.py
index ff18608576..e95c0c7e09 100644
--- a/lms/djangoapps/shoppingcart/processors/__init__.py
+++ b/lms/djangoapps/shoppingcart/processors/__init__.py
@@ -9,8 +9,9 @@ The specific implementation is determined at runtime using Django settings:
 
 """
 
-from django.conf import settings
+from __future__ import absolute_import
 
+from django.conf import settings
 
 # Import the processor implementation, using `CC_PROCESSOR_NAME`
 # as the name of the Python module in `shoppingcart.processors`
diff --git a/lms/djangoapps/shoppingcart/processors/exceptions.py b/lms/djangoapps/shoppingcart/processors/exceptions.py
index fbb8c4ac0a..98ef8935ea 100644
--- a/lms/djangoapps/shoppingcart/processors/exceptions.py
+++ b/lms/djangoapps/shoppingcart/processors/exceptions.py
@@ -1,3 +1,8 @@
+"""
+Payment processing exceptions
+"""
+from __future__ import absolute_import
+
 from shoppingcart.exceptions import PaymentException
 
 
diff --git a/lms/djangoapps/shoppingcart/processors/helpers.py b/lms/djangoapps/shoppingcart/processors/helpers.py
index 78c9e63308..d0dbc87e77 100644
--- a/lms/djangoapps/shoppingcart/processors/helpers.py
+++ b/lms/djangoapps/shoppingcart/processors/helpers.py
@@ -3,6 +3,8 @@ Helper methods for credit card processing modules.
 These methods should be shared among all processor implementations,
 but should NOT be imported by modules outside this package.
 """
+from __future__ import absolute_import
+
 from django.conf import settings
 
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
diff --git a/lms/djangoapps/shoppingcart/processors/tests/test_CyberSource2.py b/lms/djangoapps/shoppingcart/processors/tests/test_CyberSource2.py
index 7a2d2a6e81..b67ef978f1 100644
--- a/lms/djangoapps/shoppingcart/processors/tests/test_CyberSource2.py
+++ b/lms/djangoapps/shoppingcart/processors/tests/test_CyberSource2.py
@@ -2,6 +2,8 @@
 """
 Tests for the newer CyberSource API implementation.
 """
+from __future__ import absolute_import
+
 import ddt
 from django.conf import settings
 from django.test import TestCase