change arguments to format_dictlist

lms/djangoapps/analytics/csvs.py

@@ -31,9 +31,16 @@ def create_csv_response(filename, header, datarows):
     return response
 
 
-def format_dictlist(dictlist):
+def format_dictlist(dictlist, features):
     """
-    Convert FROM [
+    Convert a list of dictionaries to be compatible with create_csv_response
+
+    `dictlist` is a list of dictionaries
+        all dictionaries should have keys from features
+    `features` is a list of features
+
+    example code:
+    dictlist = [
         {
             'label1': 'value-1,1',
             'label2': 'value-1,2',
@@ -48,32 +55,26 @@ def format_dictlist(dictlist):
         }
     ]
 
-    TO {
-        'header': ['label1', 'label2', 'label3', 'label4'],
-        'datarows': [['value-1,1', 'value-1,2', 'value-1,3', 'value-1,4'],
-                     ['value-2,1', 'value-2,2', 'value-2,3', 'value-2,4']]
-    }
+    header, datarows = format_dictlist(dictlist, ['label1', 'label4'])
 
-    Assumes all keys for input dicts are the same.
+    # results in
+    header = ['label1', 'label4']
+    datarows = [['value-1,1', 'value-1,4'],
+                ['value-2,1', 'value-2,4']]
+    }
     """
 
-    if len(dictlist) > 0:
-        header = dictlist[0].keys()
-    else:
-        header = []
-
     def dict_to_entry(dct):
-        """ Convert dictionary to list for a csv row """
-        ordered = sorted(dct.items(), key=lambda (k, v): header.index(k))
+        """ Convert dictionary to a list for a csv row """
+        relevant_items = [(k, v) for (k, v) in dct.items() if k in features]
+        ordered = sorted(relevant_items, key=lambda (k, v): header.index(k))
         vals = [v for (_, v) in ordered]
         return vals
 
+    header = features
     datarows = map(dict_to_entry, dictlist)
 
-    return {
-        'header': header,
-        'datarows': datarows,
-    }
+    return header, datarows
 
 
 def format_instances(instances, features):

lms/djangoapps/analytics/tests/test_csvs.py

@@ -41,7 +41,7 @@ class TestAnalyticsFormatDictlist(TestCase):
     """ Test format_dictlist method """
 
     def test_format_dictlist(self):
-        data_in = [
+        dictlist = [
             {
                 'label1': 'value-1,1',
                 'label2': 'value-1,2',
@@ -53,22 +53,23 @@ class TestAnalyticsFormatDictlist(TestCase):
                 'label2': 'value-2,2',
                 'label3': 'value-2,3',
                 'label4': 'value-2,4',
-            },
+            }
         ]
 
-        data_out = {
-            'header': ['label1', 'label2', 'label3', 'label4'],
-            'datarows': [['value-1,1', 'value-1,2', 'value-1,3', 'value-1,4'],
-                         ['value-2,1', 'value-2,2', 'value-2,3', 'value-2,4']],
-        }
+        features = ['label1', 'label4']
+        header, datarows = format_dictlist(dictlist, features)
 
-        self.assertEqual(format_dictlist(data_in), data_out)
+        ideal_header = ['label1', 'label4']
+        ideal_datarows = [['value-1,1', 'value-1,4'],
+                          ['value-2,1', 'value-2,4']]
+
+        self.assertEqual(header, ideal_header)
+        self.assertEqual(datarows, ideal_datarows)
 
     def test_format_dictlist_empty(self):
-        self.assertEqual(format_dictlist([]), {
-            'header': [],
-            'datarows': [],
-        })
+        header, datarows = format_dictlist([], [])
+        self.assertEqual(header, [])
+        self.assertEqual(datarows, [])
 
     def test_create_csv_response(self):
         header = ['Name', 'Email']

lms/djangoapps/analytics/tests/test_distributions.py

@@ -19,7 +19,7 @@ class TestAnalyticsDistributions(TestCase):
             profile__year_of_birth=i + 1930
         ) for i in xrange(30)]
 
-        self.ces = tuple(CourseEnrollment.objects.create(course_id=self.course_id, user=user) for user in self.users)
+        self.ces = [CourseEnrollment.objects.create(course_id=self.course_id, user=user) for user in self.users]
 
     @raises(ValueError)
     def test_profile_distribution_bad_feature(self):
@@ -53,13 +53,13 @@ class TestAnalyticsDistributionsNoData(TestCase):
     def setUp(self):
         self.course_id = 'some/robot/course/id'
 
-        self.users = tuple(UserFactory(
+        self.users = [UserFactory(
             profile__year_of_birth=i + 1930,
-        ) for i in xrange(5))
+        ) for i in xrange(5)]
 
-        self.nodata_users = tuple(UserFactory(
+        self.nodata_users = [UserFactory(
             profile__year_of_birth=None,
-        ) for _ in xrange(4))
+        ) for _ in xrange(4)]
 
         self.users += self.nodata_users
 

lms/djangoapps/instructor/views/api.py

@@ -279,8 +279,8 @@ def enrolled_students_features(request, course_id, csv=False):
         )
         return response
     else:
-        formatted = analytics.csvs.format_dictlist(student_data)
-        return analytics.csvs.create_csv_response("enrolled_profiles.csv", formatted['header'], formatted['datarows'])
+        header, datarows = analytics.csvs.format_dictlist(student_data)
+        return analytics.csvs.create_csv_response("enrolled_profiles.csv", header, datarows)
 
 
 @ensure_csrf_cookie