Pylint errors

common/lib/xmodule/xmodule/modulestore/mongo/__init__.py

+"""
+Provide names as exported by older mongo.py module
+"""
+
 from xmodule.modulestore.mongo.base import MongoModuleStore, MongoKeyValueStore, MongoUsage
 
 # Backwards compatibility for prod systems that refererence

common/lib/xmodule/xmodule/modulestore/mongo/base.py

+"""
+Modulestore backed by Mongodb.
+
+Stores individual XModules as single documents with the following
+structure:
+
+{
+    '_id': <location.as_dict>,
+    'metadata': <dict containing all Scope.settings fields>
+    'definition': <dict containing all Scope.content fields>
+    'definition.children': <list of all child location.url()s>
+}
+"""
+
 import pymongo
 import sys
 import logging
@@ -19,8 +33,7 @@ from xblock.runtime import DbModel, KeyValueStore, InvalidScopeError
 from xblock.core import Scope
 
 from xmodule.modulestore import ModuleStoreBase, Location, namedtuple_to_son
-from xmodule.modulestore.exceptions import (ItemNotFoundError,
-                         DuplicateItemError)
+from xmodule.modulestore.exceptions import ItemNotFoundError, DuplicateItemError
 from xmodule.modulestore.inheritance import own_metadata, INHERITABLE_METADATA, inherit_metadata
 
 log = logging.getLogger(__name__)
@@ -32,6 +45,7 @@ log = logging.getLogger(__name__)
 
 def get_course_id_no_run(location):
     '''
+    Return the first two components of the course_id for this location (org/course)
     '''
     return "/".join([location.org, location.course])
 
@@ -615,6 +629,9 @@ class MongoModuleStore(ModuleStoreBase):
         return item
 
     def fire_updated_modulestore_signal(self, course_id, location):
+        """
+        Send a signal using `self.modulestore_update_signal`, if that has been set
+        """
         if self.modulestore_update_signal is not None:
             self.modulestore_update_signal.send(self, modulestore=self, course_id=course_id,
                                                 location=location)
@@ -758,5 +775,3 @@ class MongoModuleStore(ModuleStoreBase):
         are loaded on demand, rather than up front
         """
         return {}
-
-

common/lib/xmodule/xmodule/modulestore/mongo/draft.py

+"""
+A ModuleStore that knows about a special version 'draft'. Modules
+marked as 'draft' are read in preference to modules without the 'draft'
+version by this ModuleStore (so, access to i4x://org/course/cat/name
+returns the i4x://org/course/cat/name@draft object if that exists,
+and otherwise returns i4x://org/course/cat/name).
+"""
+
 from datetime import datetime
 
 from xmodule.modulestore import Location, namedtuple_to_son
@@ -217,7 +225,6 @@ class DraftModuleStore(MongoModuleStore):
 
     def _query_children_for_cache_children(self, items):
         # first get non-draft in a round-trip
-        queried_children = []
         to_process_non_drafts = super(DraftModuleStore, self)._query_children_for_cache_children(items)
 
         to_process_dict = {}
@@ -243,7 +250,6 @@ class DraftModuleStore(MongoModuleStore):
                 to_process_dict[draft_as_non_draft_loc] = draft
 
         # convert the dict - which is used for look ups - back into a list
-        for key, value in to_process_dict.iteritems():
-            queried_children.append(value)
+        queried_children = to_process_dict.values()
 
         return queried_children

common/lib/xmodule/xmodule/modulestore/xml_exporter.py

+"""
+Methods for exporting course data to XML
+"""
+
 import logging
 from xmodule.modulestore import Location
 from xmodule.modulestore.inheritance import own_metadata
 from fs.osfs import OSFS
 from json import dumps
 import json
-from json.encoder import JSONEncoder
 import datetime
 
+
 class EdxJSONEncoder(json.JSONEncoder):
+    """
+    Custom JSONEncoder that handles `Location` and `datetime.datetime` objects.
+
+    `Location`s are encoded as their url string form, and `datetime`s as
+    ISO date strings
+    """
     def default(self, obj):
         if isinstance(obj, Location):
             return obj.url()
@@ -22,7 +32,19 @@ class EdxJSONEncoder(json.JSONEncoder):
         else:
             return super(EdxJSONEncoder, self).default(obj)
 
+
 def export_to_xml(modulestore, contentstore, course_location, root_dir, course_dir, draft_modulestore=None):
+    """
+    Export all modules from `modulestore` and content from `contentstore` as xml to `root_dir`.
+
+    `modulestore`: A `ModuleStore` object that is the source of the modules to export
+    `contentstore`: A `ContentStore` object that is the source of the content to export
+    `course_location`: The `Location` of the `CourseModuleDescriptor` to export
+    `root_dir`: The directory to write the exported xml to
+    `course_dir`: The name of the directory inside `root_dir` to write the course content to
+    `draft_modulestore`: An optional `DraftModuleStore` that contains draft content, which will be exported
+        alongside the public content in the course.
+    """
 
     course = modulestore.get_item(course_location)
 

common/lib/xmodule/xmodule/tests/test_date_utils.py

-# Tests for xmodule.util.date_utils
+"""Tests for xmodule.util.date_utils"""
 
 from nose.tools import assert_equals, assert_false
 from xmodule.util.date_utils import get_default_time_display, almost_same_datetime
@@ -19,6 +19,7 @@ def test_get_default_time_display():
         "Mar 12, 1992 at 15:03",
         get_default_time_display(test_time, False))
 
+
 def test_get_default_time_display_notz():
     test_time = datetime(1992, 3, 12, 15, 3, 30)
     assert_equals(
@@ -31,8 +32,10 @@ def test_get_default_time_display_notz():
         "Mar 12, 1992 at 15:03",
         get_default_time_display(test_time, False))
 
+
 # pylint: disable=W0232
 class NamelessTZ(tzinfo):
+    """Static timezone for testing"""
 
     def utcoffset(self, _dt):
         return timedelta(hours=-3)
@@ -40,6 +43,7 @@ class NamelessTZ(tzinfo):
     def dst(self, _dt):
         return timedelta(0)
 
+
 def test_get_default_time_display_no_tzname():
     assert_equals("", get_default_time_display(None))
     test_time = datetime(1992, 3, 12, 15, 3, 30, tzinfo=NamelessTZ())
@@ -53,6 +57,7 @@ def test_get_default_time_display_no_tzname():
         "Mar 12, 1992 at 15:03",
         get_default_time_display(test_time, False))
 
+
 def test_almost_same_datetime():
     assert almost_same_datetime(
         datetime(2013, 5, 3, 10, 20, 30),

common/lib/xmodule/xmodule/tests/test_export.py

+"""
+Tests of XML export
+"""
+
 import unittest
 import pytz
 
 from datetime import datetime, timedelta, tzinfo
 from fs.osfs import OSFS
-from mock import Mock
 from path import path
 from tempfile import mkdtemp
 import shutil
@@ -136,19 +139,22 @@ class RoundTripTestCase(unittest.TestCase):
 
 
 class TestEdxJsonEncoder(unittest.TestCase):
+    """
+    Tests for xml_exporter.EdxJSONEncoder
+    """
     def setUp(self):
         self.encoder = EdxJSONEncoder()
 
         class OffsetTZ(tzinfo):
             """A timezone with non-None utcoffset"""
-            def utcoffset(self, dt):
+            def utcoffset(self, _dt):
                 return timedelta(hours=4)
 
         self.offset_tz = OffsetTZ()
 
         class NullTZ(tzinfo):
             """A timezone with None as its utcoffset"""
-            def utcoffset(self, dt):
+            def utcoffset(self, _dt):
                 return None
         self.null_utc_tz = NullTZ()
 

common/lib/xmodule/xmodule/util/date_utils.py

+"""
+Convenience methods for working with datetime objects
+"""
+
 import datetime
 def get_default_time_display(dt, show_timezone=True):
     """