diff --git a/openedx/core/lib/django_test_client_utils.py b/openedx/core/lib/django_test_client_utils.py
index 47d57dec65..42d67f8fe9 100644
--- a/openedx/core/lib/django_test_client_utils.py
+++ b/openedx/core/lib/django_test_client_utils.py
@@ -2,6 +2,9 @@
 This file includes the monkey-patch for requests' PATCH method, as we are using
 older version of django that does not contains the PATCH method in its test client.
 """
+
+# pylint: disable=protected-access
+
 from __future__ import unicode_literals
 
 from urlparse import urlparse
@@ -13,11 +16,13 @@ BOUNDARY = 'BoUnDaRyStRiNg'
 MULTIPART_CONTENT = 'multipart/form-data; boundary=%s' % BOUNDARY
 
 
-def request_factory_patch(self, path, data={}, content_type=MULTIPART_CONTENT, **extra):
+def request_factory_patch(self, path, data=None, content_type=MULTIPART_CONTENT, **extra):
     """
     Construct a PATCH request.
     """
-    patch_data = self._encode_data(data, content_type)
+    # pylint: disable=invalid-name
+
+    patch_data = self._encode_data(data or {}, content_type)
 
     parsed = urlparse(path)
     r = {
@@ -32,11 +37,11 @@ def request_factory_patch(self, path, data={}, content_type=MULTIPART_CONTENT, *
     return self.request(**r)
 
 
-def client_patch(self, path, data={}, content_type=MULTIPART_CONTENT, follow=False, **extra):
+def client_patch(self, path, data=None, content_type=MULTIPART_CONTENT, follow=False, **extra):
     """
     Send a resource to the server using PATCH.
     """
-    response = super(Client, self).patch(path, data=data, content_type=content_type, **extra)
+    response = super(Client, self).patch(path, data=data or {}, content_type=content_type, **extra)
     if follow:
         response = self._handle_redirects(response, **extra)
     return response
diff --git a/openedx/core/lib/logsettings.py b/openedx/core/lib/logsettings.py
index 05b2d4f0cd..593df6b323 100644
--- a/openedx/core/lib/logsettings.py
+++ b/openedx/core/lib/logsettings.py
@@ -1,3 +1,5 @@
+"""Get log settings."""
+
 import os
 import platform
 import sys
diff --git a/openedx/core/lib/rooted_paths.py b/openedx/core/lib/rooted_paths.py
index 3339d6471d..5a72fd70c6 100644
--- a/openedx/core/lib/rooted_paths.py
+++ b/openedx/core/lib/rooted_paths.py
@@ -1,3 +1,5 @@
+"""Provides rooted_glob, for finding relative glob paths in another director."""
+
 import glob2
 
 
diff --git a/openedx/core/lib/tempdir.py b/openedx/core/lib/tempdir.py
index b3f10b22e0..8d440ad14c 100644
--- a/openedx/core/lib/tempdir.py
+++ b/openedx/core/lib/tempdir.py
@@ -6,7 +6,7 @@ import shutil
 import tempfile
 
 
-def mkdtemp_clean(suffix="", prefix="tmp", dir=None):
+def mkdtemp_clean(suffix="", prefix="tmp", dir=None):   # pylint: disable=redefined-builtin
     """Just like mkdtemp, but the directory will be deleted when the process ends."""
     the_dir = tempfile.mkdtemp(suffix=suffix, prefix=prefix, dir=dir)
     atexit.register(cleanup_tempdir, the_dir)