diff --git a/common/lib/xmodule/xmodule/modulestore/tests/__init__.py b/common/lib/xmodule/xmodule/modulestore/tests/__init__.py
index 2759f2540c34..e69de29bb2d1 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/__init__.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/__init__.py
@@ -1,10 +0,0 @@
-from path import path
-
-# from ~/mitx_all/mitx/common/lib/xmodule/xmodule/modulestore/tests/
-# to   ~/mitx_all/mitx/common/test
-TEST_DIR = path(__file__).abspath().dirname()
-for i in range(5):
-    TEST_DIR = TEST_DIR.dirname()
-TEST_DIR = TEST_DIR / 'test'
-
-DATA_DIR = TEST_DIR / 'data'
diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py b/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
index c149724cc7ec..69ba9ad94b92 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py
@@ -1,18 +1,18 @@
-import pymongo
+from pprint import pprint
 
 from nose.tools import assert_equals, assert_raises, assert_not_equals, assert_false
-from pprint import pprint
+import pymongo
+from uuid import uuid4
 
 from xblock.core import Scope
 from xblock.runtime import KeyValueStore, InvalidScopeError
 
+from xmodule.tests import DATA_DIR
 from xmodule.modulestore import Location
 from xmodule.modulestore.mongo import MongoModuleStore, MongoKeyValueStore
 from xmodule.modulestore.xml_importer import import_from_xml
 
-from .test_modulestore import check_path_to_location
-from . import DATA_DIR
-from uuid import uuid4
+from xmodule.modulestore.tests.test_modulestore import check_path_to_location
 
 
 HOST = 'localhost'
diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_xml.py b/common/lib/xmodule/xmodule/modulestore/tests/test_xml.py
index c3b7ea58bc58..181985061478 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_xml.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_xml.py
@@ -1,12 +1,12 @@
 import os.path
 
+from nose.tools import assert_raises
+
 from xmodule.course_module import CourseDescriptor
 from xmodule.modulestore.xml import XMLModuleStore
 
-from nose.tools import assert_raises
-
-from .test_modulestore import check_path_to_location
-from . import DATA_DIR
+from xmodule.tests import DATA_DIR
+from xmodule.modulestore.tests.test_modulestore import check_path_to_location
 
 
 class TestXMLModuleStore(object):
diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_xml_exporter.py b/common/lib/xmodule/xmodule/modulestore/tests/test_xml_exporter.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/common/lib/xmodule/xmodule/modulestore/xml_exporter.py b/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
index c9d6e96761d9..ebf906787f1a 100644
--- a/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
+++ b/common/lib/xmodule/xmodule/modulestore/xml_exporter.py
@@ -38,7 +38,7 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
     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
+    `contentstore`: A `ContentStore` object that is the source of the content to export, can be None
     `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
@@ -46,7 +46,12 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
         alongside the public content in the course.
     """
 
-    course = modulestore.get_item(course_location)
+    # we use get_instance instead of get_item to support modulestores
+    # that can't guarantee that definitions are unique
+    course = modulestore.get_instance(
+        course_location.course_id,
+        course_location
+    )
 
     fs = OSFS(root_dir)
     export_fs = fs.makeopendir(course_dir)
@@ -56,7 +61,8 @@ def export_to_xml(modulestore, contentstore, course_location, root_dir, course_d
         course_xml.write(xml)
 
     # export the static assets
-    contentstore.export_all_for_course(course_location, root_dir + '/' + course_dir + '/static/')
+    if contentstore:
+        contentstore.export_all_for_course(course_location, root_dir + '/' + course_dir + '/static/')
 
     # export the static tabs
     export_extra_content(export_fs, modulestore, course_location, 'static_tab', 'tabs', '.html')
diff --git a/common/lib/xmodule/xmodule/tests/__init__.py b/common/lib/xmodule/xmodule/tests/__init__.py
index f599e0dd3bb9..1f5f1ed691ce 100644
--- a/common/lib/xmodule/xmodule/tests/__init__.py
+++ b/common/lib/xmodule/xmodule/tests/__init__.py
@@ -7,19 +7,24 @@
 
 """
 
-import unittest
+import json
 import os
+import unittest
+
 import fs
 import fs.osfs
-
 import numpy
-
-import json
+from mock import Mock
+from path import path
 
 import calc
-import xmodule
-from xmodule.x_module import ModuleSystem
-from mock import Mock
+from xmodule.x_module import ModuleSystem, XModuleDescriptor
+
+
+# Location of common test DATA directory
+# '../../../../edx-platform/common/test/data/'
+MODULE_DIR = path(__file__).dirname()
+DATA_DIR = path.joinpath(*MODULE_DIR.splitall()[:-4]) / 'test/data/'
 
 
 open_ended_grading_interface = {
@@ -67,7 +72,7 @@ def setUp(self):
         pass
 
     def test_load_class(self):
-        vc = xmodule.x_module.XModuleDescriptor.load_class('video')
+        vc = XModuleDescriptor.load_class('video')
         vc_str = "<class 'xmodule.video_module.VideoDescriptor'>"
         self.assertEqual(str(vc), vc_str)
 
diff --git a/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py b/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
index 4fd0ddccf7bd..8f703239a9d2 100644
--- a/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
+++ b/common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
@@ -1,8 +1,19 @@
+"""
+Tests for the various pieces of the CombinedOpenEndedGrading system
+
+OpenEndedChild
+OpenEndedModule
+
+"""
+
+from datetime import datetime
 import json
-from mock import Mock, MagicMock, ANY
+import logging
 import unittest
 
-from test_util_open_ended import MockQueryDict, DummyModulestore
+from lxml import etree
+from mock import Mock, MagicMock, ANY
+from pytz import UTC
 
 from xmodule.open_ended_grading_classes.openendedchild import OpenEndedChild
 from xmodule.open_ended_grading_classes.open_ended_module import OpenEndedModule
@@ -10,30 +21,16 @@
 from xmodule.open_ended_grading_classes.grading_service_module import GradingServiceError
 from xmodule.combined_open_ended_module import CombinedOpenEndedModule
 from xmodule.modulestore import Location
-
-from lxml import etree
+from xmodule.tests import get_test_system, test_util_open_ended
+from xmodule.tests.test_util_open_ended import MockQueryDict, DummyModulestore
 import capa.xqueue_interface as xqueue_interface
-from datetime import datetime
-from pytz import UTC
-import logging
 
-log = logging.getLogger(__name__)
 
-from . import get_test_system
+log = logging.getLogger(__name__)
 
 ORG = 'edX'
 COURSE = 'open_ended'      # name of directory with course data
 
-import test_util_open_ended
-
-"""
-Tests for the various pieces of the CombinedOpenEndedGrading system
-
-OpenEndedChild
-OpenEndedModule
-
-"""
-
 
 class OpenEndedChildTest(unittest.TestCase):
     """
diff --git a/common/lib/xmodule/xmodule/tests/test_conditional.py b/common/lib/xmodule/xmodule/tests/test_conditional.py
index b28d23636937..95472a62ede9 100644
--- a/common/lib/xmodule/xmodule/tests/test_conditional.py
+++ b/common/lib/xmodule/xmodule/tests/test_conditional.py
@@ -1,22 +1,21 @@
 
+from ast import literal_eval
 import json
 import unittest
+
 from fs.memoryfs import MemoryFS
-from ast import literal_eval
 from mock import Mock, patch
 
 from xmodule.error_module import NonStaffErrorDescriptor
 from xmodule.modulestore import Location
 from xmodule.modulestore.xml import ImportSystem, XMLModuleStore
 from xmodule.conditional_module import ConditionalModule
+from xmodule.tests import DATA_DIR, get_test_system
 
-from xmodule.tests.test_export import DATA_DIR
 
 ORG = 'test_org'
 COURSE = 'conditional'      # name of directory with course data
 
-from . import get_test_system
-
 
 class DummySystem(ImportSystem):
 
diff --git a/common/lib/xmodule/xmodule/tests/test_export.py b/common/lib/xmodule/xmodule/tests/test_export.py
index 91ef1bae5750..d9b80422e99b 100644
--- a/common/lib/xmodule/xmodule/tests/test_export.py
+++ b/common/lib/xmodule/xmodule/tests/test_export.py
@@ -2,28 +2,19 @@
 Tests of XML export
 """
 
+from datetime import datetime, timedelta, tzinfo
+from tempfile import mkdtemp
 import unittest
-import pytz
+import shutil
 
-from datetime import datetime, timedelta, tzinfo
+import pytz
 from fs.osfs import OSFS
 from path import path
-from tempfile import mkdtemp
-import shutil
 
+from xmodule.modulestore import Location
 from xmodule.modulestore.xml import XMLModuleStore
 from xmodule.modulestore.xml_exporter import EdxJSONEncoder
-
-from xmodule.modulestore import Location
-
-# from ~/mitx_all/mitx/common/lib/xmodule/xmodule/tests/
-# to   ~/mitx_all/mitx/common/test
-TEST_DIR = path(__file__).abspath().dirname()
-for i in range(4):
-    TEST_DIR = TEST_DIR.dirname()
-TEST_DIR = TEST_DIR / 'test'
-
-DATA_DIR = TEST_DIR / 'data'
+from xmodule.tests import DATA_DIR
 
 
 def strip_filenames(descriptor):
diff --git a/common/lib/xmodule/xmodule/tests/test_import.py b/common/lib/xmodule/xmodule/tests/test_import.py
index fb1bed2d3ab0..b6758dc9179e 100644
--- a/common/lib/xmodule/xmodule/tests/test_import.py
+++ b/common/lib/xmodule/xmodule/tests/test_import.py
@@ -1,20 +1,21 @@
 # -*- coding: utf-8 -*-
 
+import datetime
 import unittest
-from fs.memoryfs import MemoryFS
 
+from fs.memoryfs import MemoryFS
 from lxml import etree
 from mock import Mock, patch
 
+from django.utils.timezone import UTC
+
 from xmodule.xml_module import is_pointer_tag
 from xmodule.modulestore import Location
 from xmodule.modulestore.xml import ImportSystem, XMLModuleStore
 from xmodule.modulestore.inheritance import compute_inherited_metadata
 from xmodule.fields import Date
+from xmodule.tests import DATA_DIR
 
-from .test_export import DATA_DIR
-import datetime
-from django.utils.timezone import UTC
 
 ORG = 'test_org'
 COURSE = 'test_course'
diff --git a/common/lib/xmodule/xmodule/tests/test_util_open_ended.py b/common/lib/xmodule/xmodule/tests/test_util_open_ended.py
index 63fb4631c982..c717d52d3146 100644
--- a/common/lib/xmodule/xmodule/tests/test_util_open_ended.py
+++ b/common/lib/xmodule/xmodule/tests/test_util_open_ended.py
@@ -1,7 +1,6 @@
-from .import get_test_system
 from xmodule.modulestore import Location
 from xmodule.modulestore.xml import XMLModuleStore
-from xmodule.tests.test_export import DATA_DIR
+from xmodule.tests import DATA_DIR, get_test_system
 
 OPEN_ENDED_GRADING_INTERFACE = {
     'url': 'blah/',
@@ -42,7 +41,7 @@ class DummyModulestore(object):
     def setup_modulestore(self, name):
         self.modulestore = XMLModuleStore(DATA_DIR, course_dirs=[name])
 
-    def get_course(self, name):
+    def get_course(self, _):
         """Get a test course by directory name.  If there's more than one, error."""
         courses = self.modulestore.get_courses()
         return courses[0]