Merge pull request #2454 from mythmon/cohort-analysis-1131143

[Bug 1131143] Add cohort analysis script.

requirements/dev.txt

@@ -9,6 +9,9 @@ django-debug-toolbar==1.2.2
 # sha256: Y6KG6ssDzV9kPX60WMbGK3DBEbRjT9jVnyfMrKS3yDo
 django-sslserver==0.14
 
+# sha256: x9txeBCraWX2bIzwOYqYydjfmC2jm0zX8WKRHriVlvo
+docutils==0.12
+
 # sha256: KF6L1zDAtv374jwy0pNr_7pAHyPKsTLocixovoDW8YI
 flake8==2.2.5
 
@@ -33,5 +36,5 @@ q==2.4
 # sha256: lJM7ZOL-CAfaBhLFdKAhwNrCjHvTxKI3I65aOeqPPQQ
 Sphinx==1.2.3
 
-# sha256: x9txeBCraWX2bIzwOYqYydjfmC2jm0zX8WKRHriVlvo
-docutils==0.12
+# sha256: kHGqy9l6mpFQlsGq8NxoSsJnKQTNh221kECF1trJgQ4
+tabulate==0.7.5

scripts/cohort_analysis.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Groups users into monthly cohorts, and analyzes drop off rate for each group.
+
+Run this script like `./manage.py runscript cohort_analysis`.
+"""
+from datetime import datetime, timedelta
+from traceback import print_exc
+
+from tabulate import tabulate
+
+from kitsune.questions.models import Answer
+from kitsune.wiki.models import Revision
+
+
+def run():
+    try:
+        run_()
+    except Exception:
+        print_exc()
+        raise
+
+
+def run_():
+    now = datetime.now()
+    boundaries = [datetime(now.year, now.month, 1)]
+    for _ in range(12):
+        first_day_of_previous_month = (boundaries[-1] - timedelta(days=1)).replace(day=1)
+        boundaries.append(first_day_of_previous_month)
+    boundaries.reverse()
+    ranges = zip(boundaries[:-1], boundaries[1:])
+
+    reports = [
+        ('L10n', Revision.objects.exclude(document__locale='en-US')),
+        ('KB', Revision.objects.filter(document__locale='en-US')),
+        ('Questions', Answer.objects.all())
+    ]
+
+    for title, queryset in reports:
+        data = report_for(queryset, ranges)
+        headers = [title] + [s.strftime('%b') for s, _ in ranges]
+        print(tabulate(data, headers=headers))
+        print
+
+
+def count_contributors_in_range(queryset, users, date_range):
+    """Of the group ``users``, count how many made a contribution in ``date_range``."""
+    start, end = date_range
+    users = set(o.creator for o in
+                queryset.filter(creator__in=users, created__gte=start, created__lt=end))
+    return len(users)
+
+
+def get_cohort(queryset, date_range):
+    start, end = date_range
+    contributions_in_range = queryset.filter(created__gte=start, created__lt=end)
+    potential_users = set(cont.creator for cont in contributions_in_range)
+
+    def is_in_cohort(u):
+        first_contrib = queryset.filter(creator=u).order_by('id')[0]
+        return start <= first_contrib.created < end
+
+    return filter(is_in_cohort, potential_users)
+
+
+def report_for(queryset, ranges):
+    for i, cohort_range in enumerate(ranges):
+        cohort_users = get_cohort(queryset, cohort_range)
+        start, end = cohort_range
+        data = []
+
+        data.append(start.strftime('%b %Y'))
+        # Fill months before the cohort started
+        for _ in range(i):
+            data.append(None)
+        data.append(len(cohort_users))
+
+        for return_range in ranges[i + 1:]:
+            returned = count_contributors_in_range(queryset, cohort_users, return_range)
+            data.append(returned)
+
+        yield data