diff --git a/common/lib/capa/capa/xqueue_interface.py b/common/lib/capa/capa/xqueue_interface.py
index f2fa94a1a4..0214488cce 100644
--- a/common/lib/capa/capa/xqueue_interface.py
+++ b/common/lib/capa/capa/xqueue_interface.py
@@ -12,7 +12,7 @@ dateformat = '%Y%m%d%H%M%S'
 
 def make_hashkey(seed):
     '''
-    Generate a string key by hashing 
+    Generate a string key by hashing
     '''
     h = hashlib.md5()
     h.update(str(seed))
@@ -20,27 +20,27 @@ def make_hashkey(seed):
 
 
 def make_xheader(lms_callback_url, lms_key, queue_name):
-    '''
+    """
     Generate header for delivery and reply of queue request.
 
     Xqueue header is a JSON-serialized dict:
         { 'lms_callback_url': url to which xqueue will return the request (string),
-          'lms_key': secret key used by LMS to protect its state (string), 
+          'lms_key': secret key used by LMS to protect its state (string),
           'queue_name': designate a specific queue within xqueue server, e.g. 'MITx-6.00x' (string)
         }
-    '''
+    """
     return json.dumps({ 'lms_callback_url': lms_callback_url,
                         'lms_key': lms_key,
                         'queue_name': queue_name })
 
 
 def parse_xreply(xreply):
-    '''
+    """
     Parse the reply from xqueue. Messages are JSON-serialized dict:
         { 'return_code': 0 (success), 1 (fail)
           'content': Message from xqueue (string)
         }
-    '''
+    """
     try:
         xreply = json.loads(xreply)
     except ValueError, err:
@@ -61,11 +61,11 @@ class XQueueInterface(object):
         self.url  = url
         self.auth = django_auth
         self.session = requests.session(auth=requests_auth)
-        
+
     def send_to_queue(self, header, body, files_to_upload=None):
-        '''
+        """
         Submit a request to xqueue.
-        
+
         header: JSON-serialized dict in the format described in 'xqueue_interface.make_xheader'
 
         body: Serialized data for the receipient behind the queueing service. The operation of
@@ -74,14 +74,16 @@ class XQueueInterface(object):
         files_to_upload: List of file objects to be uploaded to xqueue along with queue request
 
         Returns (error_code, msg) where error_code != 0 indicates an error
-        '''
+        """
         # Attempt to send to queue
         (error, msg) = self._send_to_queue(header, body, files_to_upload)
 
-        if error and (msg == 'login_required'): # Log in, then try again
+        # Log in, then try again
+        if error and (msg == 'login_required'):
             self._login()
             if files_to_upload is not None:
-                for f in files_to_upload: # Need to rewind file pointers
+                # Need to rewind file pointers
+                for f in files_to_upload:
                     f.seek(0)
             (error, msg) = self._send_to_queue(header, body, files_to_upload)
 
@@ -91,18 +93,18 @@ class XQueueInterface(object):
     def _login(self):
         payload = { 'username': self.auth['username'],
                     'password': self.auth['password'] }
-        return self._http_post(self.url+'/xqueue/login/', payload)
+        return self._http_post(self.url + '/xqueue/login/', payload)
 
 
     def _send_to_queue(self, header, body, files_to_upload):
         payload = {'xqueue_header': header,
                    'xqueue_body'  : body}
-        files = {} 
+        files = {}
         if files_to_upload is not None:
             for f in files_to_upload:
                 files.update({ f.name: f })
 
-        return self._http_post(self.url+'/xqueue/submit/', payload, files=files)
+        return self._http_post(self.url + '/xqueue/submit/', payload, files=files)
 
 
     def _http_post(self, url, data, files=None):
@@ -111,7 +113,7 @@ class XQueueInterface(object):
         except requests.exceptions.ConnectionError, err:
             log.error(err)
             return (1, 'cannot connect to server')
-        
+
         if r.status_code not in [200]:
             return (1, 'unexpected HTTP status code [%d]' % r.status_code)