Merge pull request #663 from edx/nate/anonymized_id_mapping

Add mgmt cmd to generate anonymized ID mapping

common/djangoapps/student/management/commands/anonymized_id_mapping.py

+# -*- coding: utf8 -*-
+"""Dump username,unique_id_for_user pairs as CSV.
+
+Give instructors easy access to the mapping from anonymized IDs to user IDs
+with a simple Django management command to generate a CSV mapping. To run, use
+the following:
+
+rake django-admin[anonymized_id_mapping,x,y,z]
+
+[Naturally, substitute the appropriate values for x, y, and z. (I.e.,
+ lms, dev, and MITx/6.002x/Circuits)]"""
+
+import csv
+
+from django.contrib.auth.models import User
+from django.core.management.base import BaseCommand, CommandError
+
+from student.models import unique_id_for_user
+
+
+class Command(BaseCommand):
+    """Add our handler to the space where django-admin looks up commands."""
+
+    # It appears that with the way Rake invokes these commands, we can't
+    # have more than one arg passed through...annoying.
+    args = ("course_id", )
+
+    help = """Export a CSV mapping usernames to anonymized ids
+
+    Exports a CSV document mapping each username in the specified course to
+    the anonymized, unique user ID.
+    """
+
+    def handle(self, *args, **options):
+        if len(args) != 1:
+            raise CommandError("Usage: unique_id_mapping %s" %
+                               " ".join(("<%s>" % arg for arg in Command.args)))
+
+        course_id = args[0]
+
+        # Generate the output filename from the course ID.
+        # Change slashes to dashes first, and then append .csv extension.
+        output_filename = course_id.replace('/', '-') + ".csv"
+
+        # Figure out which students are enrolled in the course
+        students = User.objects.filter(courseenrollment__course_id=course_id)
+        if len(students) == 0:
+            self.stdout.write("No students enrolled in %s" % course_id)
+            return
+
+        # Write mapping to output file in CSV format with a simple header
+        try:
+            with open(output_filename, 'wb') as output_file:
+                csv_writer = csv.writer(output_file)
+                csv_writer.writerow(("User ID", "Anonymized user ID"))
+                for student in students:
+                    csv_writer.writerow((student.id, unique_id_for_user(student)))
+        except IOError:
+            raise CommandError("Error writing to file: %s" % output_filename)
+