updated the csv reader to make the csv output compatible across both python versions

updated the csv reader to make the csv output compatible across both python versions

added the encoding argument to unicodecsv.DictReader method

updated the csv file read process to accomodate different input types

changes made to fix issues with UniversalNewLineIterator

changes made as suggested

changes made as suggested

changes made to fulfill quality check requirement to pass quality check

minor changes

lms/djangoapps/instructor_task/tasks_helper/misc.py

@@ -9,9 +9,10 @@ import logging
 from collections import OrderedDict
 from datetime import datetime
 from time import time
-
-import six
+import csv
 import unicodecsv
+import six
+
 from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
 from django.core.files.storage import DefaultStorage
@@ -140,6 +141,27 @@ def upload_proctored_exam_results_report(_xmodule_instance_args, _entry_id, cour
     return task_progress.update_task_state(extra_meta=current_step)
 
 
+def _get_csv_file_content(csv_file):
+    """
+    returns appropriate csv file content based on input and output is
+    compatible with python versions
+    """
+    if (not isinstance(csv_file, str)) and six.PY3:
+        content = csv_file.read()
+    else:
+        content = csv_file
+
+    if isinstance(content, bytes):
+        csv_content = content.decode('utf-8')
+    else:
+        csv_content = content
+
+    if six.PY3:
+        return csv_content
+    else:
+        return UniversalNewlineIterator(csv_content)
+
+
 def cohort_students_and_upload(_xmodule_instance_args, _entry_id, course_id, task_input, action_name):
     """
     Within a given course, cohort students in bulk, then upload the results
@@ -151,7 +173,12 @@ def cohort_students_and_upload(_xmodule_instance_args, _entry_id, course_id, tas
     # Iterate through rows to get total assignments for task progress
     with DefaultStorage().open(task_input['file_name']) as f:
         total_assignments = 0
-        for _line in unicodecsv.DictReader(UniversalNewlineIterator(f)):
+        if six.PY3:
+            reader = csv.DictReader(_get_csv_file_content(f).splitlines())
+        else:
+            reader = unicodecsv.DictReader(_get_csv_file_content(f), encoding='utf-8')
+
+        for _line in reader:
             total_assignments += 1
 
     task_progress = TaskProgress(action_name, total_assignments, start_time)
@@ -166,7 +193,13 @@ def cohort_students_and_upload(_xmodule_instance_args, _entry_id, course_id, tas
     cohorts_status = {}
 
     with DefaultStorage().open(task_input['file_name']) as f:
-        for row in unicodecsv.DictReader(UniversalNewlineIterator(f), encoding='utf-8'):
+
+        if six.PY3:
+            reader = csv.DictReader(_get_csv_file_content(f).splitlines())
+        else:
+            reader = unicodecsv.DictReader(_get_csv_file_content(f), encoding='utf-8')
+
+        for row in reader:
             # Try to use the 'email' field to identify the user.  If it's not present, use 'username'.
             username_or_email = row.get('email') or row.get('username')
             cohort_name = row.get('cohort') or ''