add course_id arg and dry run and csv file options

Massive code clean-up as well.

lms/djangoapps/courseware/management/commands/reset_3091_exam_attempts.py

 #!/usr/bin/python
-#
-# 19-Sep-13 ichuang@mit.edu
-
 import csv
-from courseware.module_tree_reset import *
-from django.core.management.base import BaseCommand
 
-#-----------------------------------------------------------------------------
+from request_cache.middleware import RequestCache
+from xmodule.modulestore.django import modulestore
+from courseware.module_tree_reset import ProctorModuleInfo
 
 from django.conf import settings
-from xmodule.modulestore.django import modulestore
 from django.dispatch import Signal
-from request_cache.middleware import RequestCache
-
 from django.core.cache import get_cache
+from django.contrib.auth.models import User
+from django.core.management.base import BaseCommand, CommandError, make_option
 
-if True:
-    CACHE = get_cache('mongo_metadata_inheritance')
-    for store_name in settings.MODULESTORE:
-        store = modulestore(store_name)
-        store.metadata_inheritance_cache_subsystem = CACHE
-        store.request_cache = RequestCache.get_request_cache()
 
-        modulestore_update_signal = Signal(providing_args=['modulestore', 'course_id', 'location'])
-        store.modulestore_update_signal = modulestore_update_signal
+CACHE = get_cache('mongo_metadata_inheritance')
+for store_name in settings.MODULESTORE:
+    store = modulestore(store_name)
+    store.metadata_inheritance_cache_subsystem = CACHE
+    store.request_cache = RequestCache.get_request_cache()
+    modulestore_update_signal = Signal(
+        providing_args=['modulestore', 'course_id', 'location'])
+    store.modulestore_update_signal = modulestore_update_signal
 
-#-----------------------------------------------------------------------------
 
 class Command(BaseCommand):
-    help = """Reset exam attempts for 3.091 exam, Fall 2013.
-Records students and problems which were reset.
-Give filename as argument.  Output is CSV file."""
+    args = "<course_id>"
+    help = """Reset exam attempts for 3.091 exam, Fall 2013. Records students \
+and problems which were reset. Takes a course id and csv output filename as \
+arguments."""
+    option_list = BaseCommand.option_list + (
+        make_option('--dry-run',
+                    dest='dry_run',
+                    action='store_true',
+                    default=False,
+                    help='Show what would be done without actually doing '
+                    'anything'),
+        make_option('--csv-output-filename',
+                    dest='csv_output_filename',
+                    action='store',
+                    default=None,
+                    help='Save stats to csv file'),
+    )
 
     def handle(self, *args, **options):
-        # fn = 'reset_3091exam.csv'
-        fn = args[0]
-
-        pminfo = ProctorModuleInfo()
-
-        students = User.objects.filter(courseenrollment__course_id=pminfo.course.id).order_by('username')
-        # students = User.objects.filter(username='ichuang')
-
-        data = []
-
-        # write out to csv file
-
-        fieldnames = ['id', 'name', 'username', 'assignment', 'problem', 'date', 'earned', 'possible']
-        fp = open(fn,'w')
-        csvf = csv.DictWriter(fp, fieldnames, dialect="excel", quotechar='"', quoting=csv.QUOTE_ALL)
-        csvf.writeheader()
-
-        cnt = 0
+        if len(args) != 1:
+            raise CommandError("insufficient arguments")
+        course_id = args[0]
+        dry_run = options['dry_run']
+        csv_file = options['csv_output_filename']
+        pminfo = ProctorModuleInfo(course_id)
+        students = User.objects.filter(
+            courseenrollment__course_id=pminfo.course.id).order_by('username')
+        failed = []
         for student in students:
-            dat = pminfo.get_assignments_attempted_and_failed(student, do_reset=True)
-            data += dat
-            for row in dat:
-                csvf.writerow(row)
-            fp.flush()
-            cnt += 1
-            #if cnt>3:
-            #    break
+            failed += pminfo.get_assignments_attempted_and_failed(
+                student, do_reset=not dry_run)
+        if csv_file:
+            self.write_to_csv(csv_file, failed)
+
+    def write_to_csv(self, file_name, failed_assignments):
+        fieldnames = ['id', 'name', 'username', 'assignment', 'problem',
+                      'date', 'earned', 'possible']
+        fp = open(file_name, 'w')
+        csvf = csv.DictWriter(fp, fieldnames, dialect="excel", quotechar='"',
+                              quoting=csv.QUOTE_ALL)
+        csvf.writeheader()
+        for assignment in failed_assignments:
+            csvf.writerow(assignment)
         fp.close()
-
-        # print data