Address review comments

common/lib/xmodule/xmodule/peer_grading_module.py

@@ -519,7 +519,7 @@ class PeerGradingModule(PeerGradingFields, XModule):
 
         def _find_corresponding_module_for_location(location):
             """
-            Find the peer grading module that links to the given location.
+            Find the peer grading module that exists at the given location.
             """
             try:
                 return self.descriptor.system.load_item(location)
@@ -528,7 +528,7 @@ class PeerGradingModule(PeerGradingFields, XModule):
                 log.error("Problem {0} does not exist in this course.".format(location))
                 raise
             except NoPathToItem:
-                # The linked problem doesn't exist.
+                # The linked problem does not have a path to it (ie is in a draft or other strange state).
                 log.error("Cannot find a path to problem {0} in this course.".format(location))
                 raise
 

common/lib/xmodule/xmodule/tests/test_peer_grading.py

@@ -175,9 +175,9 @@ class PeerGradingModuleScoredTest(unittest.TestCase, DummyModulestore):
 
         # Ensure that it cannot find any peer grading.
         html = peer_grading.peer_grading()
-        self.assertNotRegexpMatches(html, "Peer-Graded")
+        self.assertNotIn("Peer-Graded", html)
 
-        #Swap for our mock class, which will find peer grading.
+        # Swap for our mock class, which will find peer grading.
         peer_grading.peer_gs = MockPeerGradingServiceProblemList()
         html = peer_grading.peer_grading()
-        self.assertRegexpMatches(html, "Peer-Graded")
\ No newline at end of file
+        self.assertIn("Peer-Graded", html)
\ No newline at end of file