python: Convert percent formatting to Python 3.6 f-strings.

Generated by pyupgrade --py36-plus.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

analytics/lib/counts.py

@@ -40,7 +40,7 @@ class CountStat:
         self.data_collector = data_collector
         # might have to do something different for bitfields
         if frequency not in self.FREQUENCIES:
-            raise AssertionError("Unknown frequency: %s" % (frequency,))
+            raise AssertionError(f"Unknown frequency: {frequency}")
         self.frequency = frequency
         if interval is not None:
             self.interval = interval
@@ -50,7 +50,7 @@ class CountStat:
             self.interval = timedelta(days=1)
 
     def __str__(self) -> str:
-        return "<CountStat: %s>" % (self.property,)
+        return f"<CountStat: {self.property}>"
 
 class LoggingCountStat(CountStat):
     def __init__(self, property: str, output_table: Type[BaseCount], frequency: str) -> None:
@@ -86,11 +86,11 @@ def process_count_stat(stat: CountStat, fill_to_time: datetime,
     elif stat.frequency == CountStat.DAY:
         time_increment = timedelta(days=1)
     else:
-        raise AssertionError("Unknown frequency: %s" % (stat.frequency,))
+        raise AssertionError(f"Unknown frequency: {stat.frequency}")
 
     verify_UTC(fill_to_time)
     if floor_to_hour(fill_to_time) != fill_to_time:
-        raise ValueError("fill_to_time must be on an hour boundary: %s" % (fill_to_time,))
+        raise ValueError(f"fill_to_time must be on an hour boundary: {fill_to_time}")
 
     fill_state = FillState.objects.filter(property=stat.property).first()
     if fill_state is None:
@@ -108,7 +108,7 @@ def process_count_stat(stat: CountStat, fill_to_time: datetime,
     elif fill_state.state == FillState.DONE:
         currently_filled = fill_state.end_time
     else:
-        raise AssertionError("Unknown value for FillState.state: %s." % (fill_state.state,))
+        raise AssertionError(f"Unknown value for FillState.state: {fill_state.state}.")
 
     if isinstance(stat, DependentCountStat):
         for dependency in stat.dependencies:

analytics/lib/fixtures.py

@@ -43,7 +43,7 @@ def generate_time_series_data(days: int=100, business_hours_base: float=10,
                       [24*non_business_hours_base] * 2
         holidays = [random() < holiday_rate for i in range(days)]
     else:
-        raise AssertionError("Unknown frequency: %s" % (frequency,))
+        raise AssertionError(f"Unknown frequency: {frequency}")
     if length < 2:
         raise AssertionError("Must be generating at least 2 data points. "
                              "Currently generating %s" % (length,))

analytics/lib/time_utils.py

@@ -19,7 +19,7 @@ def time_range(start: datetime, end: datetime, frequency: str,
         end = floor_to_day(end)
         step = timedelta(days=1)
     else:
-        raise AssertionError("Unknown frequency: %s" % (frequency,))
+        raise AssertionError(f"Unknown frequency: {frequency}")
 
     times = []
     if min_length is not None:

analytics/management/commands/analyze_user_activity.py

@@ -26,9 +26,9 @@ def analyze_activity(options: Dict[str, Any]) -> None:
         total_duration += duration
         print("%-*s%s" % (37, user_profile.email, duration,))
 
-    print("\nTotal Duration:                      %s" % (total_duration,))
+    print(f"\nTotal Duration:                      {total_duration}")
-    print("\nTotal Duration in minutes:           %s" % (total_duration.total_seconds() / 60.,))
+    print(f"\nTotal Duration in minutes:           {total_duration.total_seconds() / 60.}")
-    print("Total Duration amortized to a month: %s" % (total_duration.total_seconds() * 30. / 60.,))
+    print(f"Total Duration amortized to a month: {total_duration.total_seconds() * 30. / 60.}")
 
 class Command(BaseCommand):
     help = """Report analytics of user activity on a per-user and realm basis.

analytics/management/commands/check_analytics_state.py

@@ -33,8 +33,7 @@ class Command(BaseCommand):
         state_file_tmp = state_file_path + "-tmp"
 
         with open(state_file_tmp, "w") as f:
-            f.write("%s|%s|%s|%s\n" % (
+            f.write(f"{int(time.time())}|{status}|{states[status]}|{message}\n")
-                int(time.time()), status, states[status], message))
         os.rename(state_file_tmp, state_file_path)
 
     def get_fill_state(self) -> Dict[str, Any]:
@@ -50,7 +49,7 @@ class Command(BaseCommand):
             try:
                 verify_UTC(last_fill)
             except TimezoneNotUTCException:
-                return {'status': 2, 'message': 'FillState not in UTC for %s' % (property,)}
+                return {'status': 2, 'message': f'FillState not in UTC for {property}'}
 
             if stat.frequency == CountStat.DAY:
                 floor_function = floor_to_day

analytics/management/commands/clear_single_stat.py

@@ -20,7 +20,7 @@ class Command(BaseCommand):
     def handle(self, *args: Any, **options: Any) -> None:
         property = options['property']
         if property not in COUNT_STATS:
-            raise CommandError("Invalid property: %s" % (property,))
+            raise CommandError(f"Invalid property: {property}")
         if not options['force']:
             raise CommandError("No action taken. Use --force.")
 

analytics/management/commands/realm_stats.py

@@ -66,7 +66,7 @@ class Command(BaseCommand):
             fraction = 0.0
         else:
             fraction = numerator / float(denominator)
-        print("%.2f%% of" % (fraction * 100,), text)
+        print(f"{fraction * 100:.2f}% of", text)
 
     def handle(self, *args: Any, **options: Any) -> None:
         if options['realms']:

analytics/management/commands/stream_stats.py

@@ -40,18 +40,18 @@ class Command(BaseCommand):
             print("%10s %d public streams and" % ("(", public_count), end=' ')
             print("%d private streams )" % (private_count,))
             print("------------")
-            print("%25s %15s %10s %12s" % ("stream", "subscribers", "messages", "type"))
+            print("{:>25} {:>15} {:>10} {:>12}".format("stream", "subscribers", "messages", "type"))
 
             for stream in streams:
                 if stream.invite_only:
                     stream_type = 'private'
                 else:
                     stream_type = 'public'
-                print("%25s" % (stream.name,), end=' ')
+                print(f"{stream.name:>25}", end=' ')
                 recipient = Recipient.objects.filter(type=Recipient.STREAM, type_id=stream.id)
                 print("%10d" % (len(Subscription.objects.filter(recipient=recipient,
                                                                 active=True)),), end=' ')
                 num_messages = len(Message.objects.filter(recipient=recipient))
                 print("%12d" % (num_messages,), end=' ')
-                print("%15s" % (stream_type,))
+                print(f"{stream_type:>15}")
             print("")

analytics/management/commands/update_analytics_counts.py

@@ -71,7 +71,7 @@ class Command(BaseCommand):
         else:
             stats = list(COUNT_STATS.values())
 
-        logger.info("Starting updating analytics counts through %s" % (fill_to_time,))
+        logger.info(f"Starting updating analytics counts through {fill_to_time}")
         if options['verbose']:
             start = time.time()
             last = start
@@ -79,13 +79,13 @@ class Command(BaseCommand):
         for stat in stats:
             process_count_stat(stat, fill_to_time)
             if options['verbose']:
-                print("Updated %s in %.3fs" % (stat.property, time.time() - last))
+                print(f"Updated {stat.property} in {time.time() - last:.3f}s")
                 last = time.time()
 
         if options['verbose']:
             print("Finished updating analytics counts through %s in %.3fs" %
                   (fill_to_time, time.time() - start))
-        logger.info("Finished updating analytics counts through %s" % (fill_to_time,))
+        logger.info(f"Finished updating analytics counts through {fill_to_time}")
 
         if settings.PUSH_NOTIFICATION_BOUNCER_URL and settings.SUBMIT_USAGE_STATISTICS:
             send_analytics_to_remote_server()

analytics/management/commands/user_stats.py

@@ -36,7 +36,7 @@ class Command(BaseCommand):
             print("%d streams" % (len(Stream.objects.filter(realm=realm)),))
 
             for user_profile in user_profiles:
-                print("%35s" % (user_profile.email,), end=' ')
+                print(f"{user_profile.email:>35}", end=' ')
                 for week in range(10):
                     print("%5d" % (self.messages_sent_by(user_profile, week),), end=' ')
                 print("")

analytics/models.py

@@ -17,7 +17,7 @@ class FillState(models.Model):
     state: int = models.PositiveSmallIntegerField()
 
     def __str__(self) -> str:
-        return "<FillState: %s %s %s>" % (self.property, self.end_time, self.state)
+        return f"<FillState: {self.property} {self.end_time} {self.state}>"
 
 # The earliest/starting end_time in FillState
 # We assume there is at least one realm
@@ -61,7 +61,7 @@ class InstallationCount(BaseCount):
         ]
 
     def __str__(self) -> str:
-        return "<InstallationCount: %s %s %s>" % (self.property, self.subgroup, self.value)
+        return f"<InstallationCount: {self.property} {self.subgroup} {self.value}>"
 
 class RealmCount(BaseCount):
     realm = models.ForeignKey(Realm, on_delete=models.CASCADE)
@@ -81,7 +81,7 @@ class RealmCount(BaseCount):
         index_together = ["property", "end_time"]
 
     def __str__(self) -> str:
-        return "<RealmCount: %s %s %s %s>" % (self.realm, self.property, self.subgroup, self.value)
+        return f"<RealmCount: {self.realm} {self.property} {self.subgroup} {self.value}>"
 
 class UserCount(BaseCount):
     user = models.ForeignKey(UserProfile, on_delete=models.CASCADE)
@@ -104,7 +104,7 @@ class UserCount(BaseCount):
         index_together = ["property", "realm", "end_time"]
 
     def __str__(self) -> str:
-        return "<UserCount: %s %s %s %s>" % (self.user, self.property, self.subgroup, self.value)
+        return f"<UserCount: {self.user} {self.property} {self.subgroup} {self.value}>"
 
 class StreamCount(BaseCount):
     stream = models.ForeignKey(Stream, on_delete=models.CASCADE)
@@ -127,5 +127,4 @@ class StreamCount(BaseCount):
         index_together = ["property", "realm", "end_time"]
 
     def __str__(self) -> str:
-        return "<StreamCount: %s %s %s %s %s>" % (
+        return f"<StreamCount: {self.stream} {self.property} {self.subgroup} {self.value} {self.id}>"
-            self.stream, self.property, self.subgroup, self.value, self.id)

analytics/tests/test_counts.py

@@ -49,7 +49,7 @@ class AnalyticsTestCase(TestCase):
     def create_user(self, **kwargs: Any) -> UserProfile:
         self.name_counter += 1
         defaults = {
-            'email': 'user%s@domain.tld' % (self.name_counter,),
+            'email': f'user{self.name_counter}@domain.tld',
             'date_joined': self.TIME_LAST_HOUR,
             'full_name': 'full_name',
             'short_name': 'short_name',
@@ -71,7 +71,7 @@ class AnalyticsTestCase(TestCase):
 
     def create_stream_with_recipient(self, **kwargs: Any) -> Tuple[Stream, Recipient]:
         self.name_counter += 1
-        defaults = {'name': 'stream name %s' % (self.name_counter,),
+        defaults = {'name': f'stream name {self.name_counter}',
                     'realm': self.default_realm,
                     'date_created': self.TIME_LAST_HOUR}
         for key, value in defaults.items():
@@ -84,7 +84,7 @@ class AnalyticsTestCase(TestCase):
 
     def create_huddle_with_recipient(self, **kwargs: Any) -> Tuple[Huddle, Recipient]:
         self.name_counter += 1
-        defaults = {'huddle_hash': 'hash%s' % (self.name_counter,)}
+        defaults = {'huddle_hash': f'hash{self.name_counter}'}
         for key, value in defaults.items():
             kwargs[key] = kwargs.get(key, value)
         huddle = Huddle.objects.create(**kwargs)
@@ -339,10 +339,10 @@ class TestCountStats(AnalyticsTestCase):
             date_created=self.TIME_ZERO-2*self.DAY)
         for minutes_ago in [0, 1, 61, 60*24+1]:
             creation_time = self.TIME_ZERO - minutes_ago*self.MINUTE
-            user = self.create_user(email='user-%s@second.analytics' % (minutes_ago,),
+            user = self.create_user(email=f'user-{minutes_ago}@second.analytics',
                                     realm=self.second_realm, date_joined=creation_time)
             recipient = self.create_stream_with_recipient(
-                name='stream %s' % (minutes_ago,), realm=self.second_realm,
+                name=f'stream {minutes_ago}', realm=self.second_realm,
                 date_created=creation_time)[1]
             self.create_message(user, recipient, date_sent=creation_time)
         self.hourly_user = get_user('user-1@second.analytics', self.second_realm)

analytics/tests/test_views.py

@@ -408,7 +408,7 @@ class TestSupportEndpoint(ZulipTestCase):
 
         def check_zulip_realm_query_result(result: HttpResponse) -> None:
             zulip_realm = get_realm("zulip")
-            self.assert_in_success_response(['<input type="hidden" name="realm_id" value="%s"' % (zulip_realm.id,),
+            self.assert_in_success_response([f'<input type="hidden" name="realm_id" value="{zulip_realm.id}"',
                                              'Zulip Dev</h3>',
                                              '<option value="1" selected>Self Hosted</option>',
                                              '<option value="2" >Limited</option>',
@@ -420,7 +420,7 @@ class TestSupportEndpoint(ZulipTestCase):
 
         def check_lear_realm_query_result(result: HttpResponse) -> None:
             lear_realm = get_realm("lear")
-            self.assert_in_success_response(['<input type="hidden" name="realm_id" value="%s"' % (lear_realm.id,),
+            self.assert_in_success_response([f'<input type="hidden" name="realm_id" value="{lear_realm.id}"',
                                              'Lear &amp; Co.</h3>',
                                              '<option value="1" selected>Self Hosted</option>',
                                              '<option value="2" >Limited</option>',
@@ -532,7 +532,7 @@ class TestSupportEndpoint(ZulipTestCase):
         cordelia = self.example_user('cordelia')
         self.login_user(cordelia)
 
-        result = self.client_post("/activity/support", {"realm_id": "%s" % (cordelia.realm_id,), "plan_type": "2"})
+        result = self.client_post("/activity/support", {"realm_id": f"{cordelia.realm_id}", "plan_type": "2"})
         self.assertEqual(result.status_code, 302)
         self.assertEqual(result["Location"], "/login/")
 
@@ -540,7 +540,7 @@ class TestSupportEndpoint(ZulipTestCase):
         self.login_user(iago)
 
         with mock.patch("analytics.views.do_change_plan_type") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (iago.realm_id,), "plan_type": "2"})
+            result = self.client_post("/activity/support", {"realm_id": f"{iago.realm_id}", "plan_type": "2"})
             m.assert_called_once_with(get_realm("zulip"), 2)
             self.assert_in_success_response(["Plan type of Zulip Dev changed from self hosted to limited"], result)
 
@@ -549,14 +549,14 @@ class TestSupportEndpoint(ZulipTestCase):
         lear_realm = get_realm('lear')
         self.login_user(cordelia)
 
-        result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "discount": "25"})
+        result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "discount": "25"})
         self.assertEqual(result.status_code, 302)
         self.assertEqual(result["Location"], "/login/")
 
         self.login('iago')
 
         with mock.patch("analytics.views.attach_discount_to_realm") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "discount": "25"})
+            result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "discount": "25"})
             m.assert_called_once_with(get_realm("lear"), 25)
             self.assert_in_success_response(["Discount of Lear &amp; Co. changed to 25 from None"], result)
 
@@ -565,19 +565,19 @@ class TestSupportEndpoint(ZulipTestCase):
         lear_realm = get_realm('lear')
         self.login_user(cordelia)
 
-        result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "status": "deactivated"})
+        result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "status": "deactivated"})
         self.assertEqual(result.status_code, 302)
         self.assertEqual(result["Location"], "/login/")
 
         self.login('iago')
 
         with mock.patch("analytics.views.do_deactivate_realm") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "status": "deactivated"})
+            result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "status": "deactivated"})
             m.assert_called_once_with(lear_realm, self.example_user("iago"))
             self.assert_in_success_response(["Lear &amp; Co. deactivated"], result)
 
         with mock.patch("analytics.views.do_send_realm_reactivation_email") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "status": "active"})
+            result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "status": "active"})
             m.assert_called_once_with(lear_realm)
             self.assert_in_success_response(["Realm reactivation email sent to admins of Lear"], result)
 
@@ -586,19 +586,19 @@ class TestSupportEndpoint(ZulipTestCase):
         lear_realm = get_realm('lear')
         self.login_user(cordelia)
 
-        result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "discount": "25"})
+        result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "discount": "25"})
         self.assertEqual(result.status_code, 302)
         self.assertEqual(result["Location"], "/login/")
 
         self.login('iago')
 
         with mock.patch("analytics.views.do_scrub_realm") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,), "scrub_realm": "scrub_realm"})
+            result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}", "scrub_realm": "scrub_realm"})
             m.assert_called_once_with(lear_realm)
             self.assert_in_success_response(["Lear &amp; Co. scrubbed"], result)
 
         with mock.patch("analytics.views.do_scrub_realm") as m:
-            result = self.client_post("/activity/support", {"realm_id": "%s" % (lear_realm.id,)})
+            result = self.client_post("/activity/support", {"realm_id": f"{lear_realm.id}"})
             m.assert_not_called()
 
 class TestGetChartDataHelpers(ZulipTestCase):

analytics/views.py

@@ -96,9 +96,9 @@ def stats_for_realm(request: HttpRequest, realm_str: str) -> HttpResponse:
     try:
         realm = get_realm(realm_str)
     except Realm.DoesNotExist:
-        return HttpResponseNotFound("Realm %s does not exist" % (realm_str,))
+        return HttpResponseNotFound(f"Realm {realm_str} does not exist")
 
-    return render_stats(request, '/realm/%s' % (realm_str,), realm.name or realm.string_id,
+    return render_stats(request, f'/realm/{realm_str}', realm.name or realm.string_id,
                         analytics_ready=is_analytics_ready(realm))
 
 @require_server_admin
@@ -106,8 +106,8 @@ def stats_for_realm(request: HttpRequest, realm_str: str) -> HttpResponse:
 def stats_for_remote_realm(request: HttpRequest, remote_server_id: str,
                            remote_realm_id: str) -> HttpResponse:
     server = RemoteZulipServer.objects.get(id=remote_server_id)
-    return render_stats(request, '/remote/%s/realm/%s' % (server.id, remote_realm_id),
+    return render_stats(request, f'/remote/{server.id}/realm/{remote_realm_id}',
-                        "Realm %s on server %s" % (remote_realm_id, server.hostname))
+                        f"Realm {remote_realm_id} on server {server.hostname}")
 
 @require_server_admin_api
 @has_request_variables
@@ -136,8 +136,8 @@ def stats_for_installation(request: HttpRequest) -> HttpResponse:
 @require_server_admin
 def stats_for_remote_installation(request: HttpRequest, remote_server_id: str) -> HttpResponse:
     server = RemoteZulipServer.objects.get(id=remote_server_id)
-    return render_stats(request, '/remote/%s/installation' % (server.id,),
+    return render_stats(request, f'/remote/{server.id}/installation',
-                        'remote Installation %s' % (server.hostname,), True, True)
+                        f'remote Installation {server.hostname}', True, True)
 
 @require_server_admin_api
 @has_request_variables
@@ -332,7 +332,7 @@ def table_filtered_to_id(table: Type[BaseCount], key_id: int) -> QuerySet:
     elif table == RemoteRealmCount:
         return RemoteRealmCount.objects.filter(realm_id=key_id)
     else:
-        raise AssertionError("Unknown table: %s" % (table,))
+        raise AssertionError(f"Unknown table: {table}")
 
 def client_label_map(name: str) -> str:
     if name == "website":
@@ -463,7 +463,7 @@ def get_realm_day_counts() -> Dict[str, Dict[str, str]]:
             else:
                 good_bad = 'neutral'
 
-            return '<td class="number %s">%s</td>' % (good_bad, cnt)
+            return f'<td class="number {good_bad}">{cnt}</td>'
 
         cnts = (format_count(raw_cnts[0], 'neutral')
                 + ''.join(map(format_count, raw_cnts[1:])))
@@ -629,7 +629,7 @@ def realm_summary_table(realm_minutes: Dict[str, float]) -> str:
         total_hours += hours
         row['hours'] = str(int(hours))
         try:
-            row['hours_per_user'] = '%.1f' % (hours / row['dau_count'],)
+            row['hours_per_user'] = '{:.1f}'.format(hours / row['dau_count'])
         except Exception:
             pass
 
@@ -709,7 +709,7 @@ def user_activity_intervals() -> Tuple[mark_safe, Dict[str, float]]:
 
     for string_id, realm_intervals in itertools.groupby(all_intervals, by_string_id):
         realm_duration = timedelta(0)
-        output += '<hr>%s\n' % (string_id,)
+        output += f'<hr>{string_id}\n'
         for email, intervals in itertools.groupby(realm_intervals, by_email):
             duration = timedelta(0)
             for interval in intervals:
@@ -723,9 +723,9 @@ def user_activity_intervals() -> Tuple[mark_safe, Dict[str, float]]:
 
         realm_minutes[string_id] = realm_duration.total_seconds() / 60
 
-    output += "\nTotal Duration:                      %s\n" % (total_duration,)
+    output += f"\nTotal Duration:                      {total_duration}\n"
-    output += "\nTotal Duration in minutes:           %s\n" % (total_duration.total_seconds() / 60.,)
+    output += f"\nTotal Duration in minutes:           {total_duration.total_seconds() / 60.}\n"
-    output += "Total Duration amortized to a month: %s" % (total_duration.total_seconds() * 30. / 60.,)
+    output += f"Total Duration amortized to a month: {total_duration.total_seconds() * 30. / 60.}"
     content = mark_safe('<pre>' + output + '</pre>')
     return content, realm_minutes
 
@@ -841,7 +841,7 @@ def ad_hoc_queries() -> List[Dict[str, str]]:
     ###
 
     for mobile_type in ['Android', 'ZulipiOS']:
-        title = '%s usage' % (mobile_type,)
+        title = f'{mobile_type} usage'
 
         query = SQL('''
             select
@@ -1284,13 +1284,13 @@ def format_date_for_activity_reports(date: Optional[datetime]) -> str:
 def user_activity_link(email: str) -> mark_safe:
     url_name = 'analytics.views.get_user_activity'
     url = reverse(url_name, kwargs=dict(email=email))
-    email_link = '<a href="%s">%s</a>' % (url, email)
+    email_link = f'<a href="{url}">{email}</a>'
     return mark_safe(email_link)
 
 def realm_activity_link(realm_str: str) -> mark_safe:
     url_name = 'analytics.views.get_realm_activity'
     url = reverse(url_name, kwargs=dict(realm_str=realm_str))
-    realm_link = '<a href="%s">%s</a>' % (url, realm_str)
+    realm_link = f'<a href="{url}">{realm_str}</a>'
     return mark_safe(realm_link)
 
 def realm_stats_link(realm_str: str) -> mark_safe:
@@ -1449,7 +1449,7 @@ def get_realm_activity(request: HttpRequest, realm_str: str) -> HttpResponse:
     try:
         admins = Realm.objects.get(string_id=realm_str).get_human_admin_users()
     except Realm.DoesNotExist:
-        return HttpResponseNotFound("Realm %s does not exist" % (realm_str,))
+        return HttpResponseNotFound(f"Realm {realm_str} does not exist")
 
     admin_emails = {admin.delivery_email for admin in admins}
 

corporate/lib/stripe.py

@@ -185,7 +185,7 @@ def do_create_stripe_customer(user: UserProfile, stripe_token: Optional[str]=Non
     # bad thing that will happen is that we will create an extra stripe
     # customer that we can delete or ignore.
     stripe_customer = stripe.Customer.create(
-        description="%s (%s)" % (realm.string_id, realm.name),
+        description=f"{realm.string_id} ({realm.name})",
         email=user.delivery_email,
         metadata={'realm_id': realm.id, 'realm_str': realm.string_id},
         source=stripe_token)

corporate/models.py

@@ -14,7 +14,7 @@ class Customer(models.Model):
     default_discount: Optional[Decimal] = models.DecimalField(decimal_places=4, max_digits=7, null=True)
 
     def __str__(self) -> str:
-        return "<Customer %s %s>" % (self.realm, self.stripe_customer_id)
+        return f"<Customer {self.realm} {self.stripe_customer_id}>"
 
 def get_customer_by_realm(realm: Realm) -> Optional[Customer]:
     return Customer.objects.filter(realm=realm).first()

corporate/tests/test_stripe.py

@@ -144,7 +144,7 @@ def normalize_fixture_data(decorated_function: CallableT,
     for i, timestamp_field in enumerate(tested_timestamp_fields):
         # Don't use (..) notation, since the matched timestamp can easily appear in other fields
         pattern_translations[
-            '"%s": 1[5-9][0-9]{8}(?![0-9-])' % (timestamp_field,)
+            f'"{timestamp_field}": 1[5-9][0-9]{{8}}(?![0-9-])'
         ] = '"%s": 1%02d%%07d' % (timestamp_field, i+1)
 
     normalized_values: Dict[str, Dict[str, str]] = {
@@ -463,8 +463,8 @@ class StripeTest(StripeTestCase):
         self.assert_not_in_success_response(['Pay annually'], response)
         for substring in [
                 'Zulip Standard', str(self.seat_count),
-                'You are using', '%s of %s licenses' % (self.seat_count, self.seat_count),
+                'You are using', f'{self.seat_count} of {self.seat_count} licenses',
-                'Your plan will renew on', 'January 2, 2013', '$%s.00' % (80 * self.seat_count,),
+                'Your plan will renew on', 'January 2, 2013', f'${80 * self.seat_count}.00',
                 'Visa ending in 4242',
                 'Update card']:
             self.assert_in_response(substring, response)
@@ -547,7 +547,7 @@ class StripeTest(StripeTestCase):
         self.assert_not_in_success_response(['Pay annually', 'Update card'], response)
         for substring in [
                 'Zulip Standard', str(123),
-                'You are using', '%s of %s licenses' % (self.seat_count, 123),
+                'You are using', f'{self.seat_count} of {123} licenses',
                 'Your plan will renew on', 'January 2, 2013', '$9,840.00',  # 9840 = 80 * 123
                 'Billed by invoice']:
             self.assert_in_response(substring, response)
@@ -618,8 +618,8 @@ class StripeTest(StripeTestCase):
             self.assert_not_in_success_response(['Pay annually'], response)
             for substring in [
                     'Zulip Standard', 'Free Trial', str(self.seat_count),
-                    'You are using', '%s of %s licenses' % (self.seat_count, self.seat_count),
+                    'You are using', f'{self.seat_count} of {self.seat_count} licenses',
-                    'Your plan will be upgraded to', 'March 2, 2012', '$%s.00' % (80 * self.seat_count,),
+                    'Your plan will be upgraded to', 'March 2, 2012', f'${80 * self.seat_count}.00',
                     'Visa ending in 4242',
                     'Update card']:
                 self.assert_in_response(substring, response)
@@ -772,7 +772,7 @@ class StripeTest(StripeTestCase):
             self.assert_not_in_success_response(['Pay annually'], response)
             for substring in [
                     'Zulip Standard', 'Free Trial', str(self.seat_count),
-                    'You are using', '%s of %s licenses' % (self.seat_count, 123),
+                    'You are using', f'{self.seat_count} of {123} licenses',
                     'Your plan will be upgraded to', 'March 2, 2012',
                     f'{80 * 123:,.2f}', 'Billed by invoice'
             ]:

corporate/views.py

@@ -114,7 +114,7 @@ def upgrade(request: HttpRequest, user: UserProfile,
             )
         return json_error(e.message, data={'error_description': e.description})
     except Exception as e:
-        billing_logger.exception("Uncaught exception in billing: %s" % (e,))
+        billing_logger.exception(f"Uncaught exception in billing: {e}")
         error_message = BillingError.CONTACT_SUPPORT
         error_description = "uncaught exception during upgrade"
         return json_error(error_message, data={'error_description': error_description})

frontend_tests/run-casper

@@ -121,7 +121,7 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
         for test_file in test_files:
             test_name = os.path.basename(test_file)
             cmd = ["node_modules/.bin/casperjs"] + remote_debug + verbose + xunit_export + ["test", test_file]
-            print("\n\n===================== %s\nRunning %s\n\n" % (test_name, " ".join(map(shlex.quote, cmd))), flush=True)
+            print("\n\n===================== {}\nRunning {}\n\n".format(test_name, " ".join(map(shlex.quote, cmd))), flush=True)
             ret = subprocess.call(cmd)
             if ret != 0:
                 return ret

puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_cron_file

@@ -36,7 +36,7 @@ def nagios_from_file(results_file: str, max_time_diff: int=60 * 2) -> 'Tuple[int
             state = pieces[2]
             data = pieces[3]
 
-    return (ret, "%s: %s" % (state, data))
+    return (ret, f"{state}: {data}")
 
 if __name__ == "__main__":
     RESULTS_FILE = sys.argv[1]

puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_queue_worker_errors

@@ -12,7 +12,7 @@ import sys
 wildcard = os.path.join("/var/log/zulip/queue_error", '*.errors')
 clean = True
 for fn in glob.glob(wildcard):
-    print('WARNING: Queue errors logged in %s' % (fn,))
+    print(f'WARNING: Queue errors logged in {fn}')
     clean = False
 
 if not clean:

puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_rabbitmq_consumers

@@ -17,7 +17,7 @@ if len(sys.argv) < 2:
     print("Please pass the name of the consumer file to check")
     exit(1)
 
-RESULTS_FILE = "/var/lib/nagios_state/check-rabbitmq-consumers-%s" % (sys.argv[1],)
+RESULTS_FILE = f"/var/lib/nagios_state/check-rabbitmq-consumers-{sys.argv[1]}"
 
 ret, result = nagios_from_file(RESULTS_FILE)
 

puppet/zulip/files/nagios_plugins/zulip_app_frontend/check_send_receive_time

@@ -88,24 +88,24 @@ states = {
 def report(state: str, timestamp: Any = None, msg: Optional[str] = None) -> None:
     now = int(time.time())
     if msg is None:
-        msg = "send time was %s" % (timestamp,)
+        msg = f"send time was {timestamp}"
     state_file_path = "/var/lib/nagios_state/check_send_receive_state"
     with open(state_file_path + ".tmp", 'w') as f:
-        f.write("%s|%s|%s|%s\n" % (now, states[state], state, msg))
+        f.write(f"{now}|{states[state]}|{state}|{msg}\n")
     os.rename(state_file_path + ".tmp", state_file_path)
-    print("%s: %s" % (state, msg))
+    print(f"{state}: {msg}")
     exit(states[state])
 
 def send_zulip(sender: zulip.Client, message: Dict[str, Any]) -> None:
     result = sender.send_message(message)
     if result["result"] != "success" and options.nagios:
-        report("CRITICAL", msg="Error sending Zulip, args were: %s, %s" % (message, result))
+        report("CRITICAL", msg=f"Error sending Zulip, args were: {message}, {result}")
 
 def get_zulips() -> List[Dict[str, Any]]:
     global queue_id, last_event_id
     res = zulip_recipient.get_events(queue_id=queue_id, last_event_id=last_event_id)
     if 'error' in res.get('result', {}):
-        report("CRITICAL", msg="Error receiving Zulips, error was: %s" % (res["msg"],))
+        report("CRITICAL", msg="Error receiving Zulips, error was: {}".format(res["msg"]))
     for event in res['events']:
         last_event_id = max(last_event_id, int(event['id']))
     # If we get a heartbeat event, that means we've been hanging for
@@ -141,10 +141,10 @@ zulip_recipient = zulip.Client(
 try:
     res = zulip_recipient.register(event_types=["message"])
     if 'error' in res.get('result', {}):
-        report("CRITICAL", msg="Error subscribing to Zulips: %s" % (res['msg'],))
+        report("CRITICAL", msg="Error subscribing to Zulips: {}".format(res['msg']))
     queue_id, last_event_id = (res['queue_id'], res['last_event_id'])
 except Exception:
-    report("CRITICAL", msg="Error subscribing to Zulips:\n%s" % (traceback.format_exc(),))
+    report("CRITICAL", msg=f"Error subscribing to Zulips:\n{traceback.format_exc()}")
 msg_to_send = str(random.getrandbits(64))
 time_start = time.time()
 
@@ -172,6 +172,6 @@ if options.nagios:
         report('WARNING', timestamp=seconds_diff)
 
 if options.munin:
-    print("sendreceive.value %s" % (seconds_diff,))
+    print(f"sendreceive.value {seconds_diff}")
 elif options.nagios:
     report('OK', timestamp=seconds_diff)

puppet/zulip/files/nagios_plugins/zulip_nagios_server/check_postgres_replication_lag

@@ -22,17 +22,17 @@ states = {
 }
 
 def report(state: str, msg: str) -> "NoReturn":
-    print("%s: %s" % (state, msg))
+    print(f"{state}: {msg}")
     exit(states[state])
 
 def get_loc_over_ssh(host: str, func: str) -> str:
     try:
         return subprocess.check_output(['ssh', host,
-                                        'psql -v ON_ERROR_STOP=1 zulip -t -c "SELECT %s()"' % (func,)],
+                                        f'psql -v ON_ERROR_STOP=1 zulip -t -c "SELECT {func}()"'],
                                        stderr=subprocess.STDOUT,
                                        universal_newlines=True)
     except subprocess.CalledProcessError as e:
-        report('CRITICAL', 'ssh failed: %s: %s' % (str(e), e.output))
+        report('CRITICAL', f'ssh failed: {str(e)}: {e.output}')
 
 def loc_to_abs_offset(loc_str: str) -> int:
     m = re.match(r'^\s*([0-9a-fA-F]+)/([0-9a-fA-F]+)\s*$', loc_str)

puppet/zulip/files/nagios_plugins/zulip_postgres_appdb/check_fts_update_log

@@ -22,7 +22,7 @@ states = {
 }
 
 def report(state: str, num: str) -> None:
-    print("%s: %s rows in fts_update_log table" % (state, num))
+    print(f"{state}: {num} rows in fts_update_log table")
     exit(states[state])
 
 conn = psycopg2.connect(database="zulip")

puppet/zulip/files/nagios_plugins/zulip_postgres_common/check_postgres_backup

@@ -13,7 +13,7 @@ states = {
 }
 
 def report(state: str, msg: str) -> None:
-    print("%s: %s" % (state, msg))
+    print(f"{state}: {msg}")
     exit(states[state])
 
 if subprocess.check_output(['psql', '-v', 'ON_ERROR_STOP=1',
@@ -28,6 +28,6 @@ except OSError:
     report('UNKNOWN', 'could not determine completion time of last Postgres backup')
 
 if datetime.now(tz=timezone.utc) - last_backup > timedelta(hours=25):
-    report('CRITICAL', 'last Postgres backup completed more than 25 hours ago: %s' % (last_backup,))
+    report('CRITICAL', f'last Postgres backup completed more than 25 hours ago: {last_backup}')
 
-report('OK', 'last Postgres backup completed less than 25 hours ago: %s' % (last_backup,))
+report('OK', f'last Postgres backup completed less than 25 hours ago: {last_backup}')

puppet/zulip/files/postgresql/pg_backup_and_purge

@@ -42,7 +42,7 @@ if is_rhel_based:
 else:
     pg_data_paths = glob.glob('/var/lib/postgresql/*/main')
 if len(pg_data_paths) != 1:
-    print("Postgres installation is not unique: %s" % (pg_data_paths,))
+    print(f"Postgres installation is not unique: {pg_data_paths}")
     sys.exit(1)
 pg_data_path = pg_data_paths[0]
 run(['env-wal-e', 'backup-push', pg_data_path])

puppet/zulip/files/postgresql/process_fts_updates

@@ -142,7 +142,7 @@ while True:
             # Catch up on any historical columns
             while True:
                 rows_updated = update_fts_columns(cursor)
-                notice = "Processed %s rows catching up" % (rows_updated,)
+                notice = f"Processed {rows_updated} rows catching up"
                 if rows_updated > 0:
                     logger.info(notice)
                 else:

puppet/zulip_ops/files/nagios_plugins/zulip_zephyr_mirror/check_personal_zephyr_mirrors

@@ -22,7 +22,7 @@ states: Dict[str, int] = {
 }
 
 def report(state: str, output: str) -> None:
-    print("%s\n%s" % (state, output))
+    print(f"{state}\n{output}")
     exit(states[state])
 
 output = ""
@@ -41,7 +41,7 @@ for results_file_name in os.listdir(RESULTS_DIR):
         down_count += 1
         this_state = "DOWN"
     last_check_ts = time.strftime("%Y-%m-%d %H:%M %Z", time.gmtime(last_check))
-    output += "%s: %s (%s)\n" % (results_file, this_state, last_check_ts)
+    output += f"{results_file}: {this_state} ({last_check_ts})\n"
 
 if down_count == 0:
     state = "OK"

puppet/zulip_ops/files/nagios_plugins/zulip_zephyr_mirror/check_user_zephyr_mirror_liveness

@@ -39,11 +39,11 @@ def report(state: str, short_msg: str, too_old: Optional[Set[Any]] = None) -> No
     too_old_data = ""
     if too_old:
         too_old_data = "\nLast call to get_message for recently out of date mirrors:\n" + "\n".join(
-            ["%16s: %s" % (user.user_profile.email,
+            ["{:>16}: {}".format(user.user_profile.email,
-                           user.last_visit.strftime("%Y-%m-%d %H:%M %Z")
+                                 user.last_visit.strftime("%Y-%m-%d %H:%M %Z")
-                           ) for user in too_old]
+                                 ) for user in too_old]
         )
-    print("%s: %s%s" % (state, short_msg, too_old_data))
+    print(f"{state}: {short_msg}{too_old_data}")
 
     exit(states[state])
 

puppet/zulip_ops/files/nagios_plugins/zulip_zephyr_mirror/check_zephyr_mirror

@@ -23,7 +23,7 @@ states: Dict[str, int] = {
 }
 
 def report(state: str, data: str, last_check: float) -> None:
-    print("%s: Last test run completed at %s\n%s" % (
+    print("{}: Last test run completed at {}\n{}".format(
         state, time.strftime("%Y-%m-%d %H:%M %Z", time.gmtime(last_check)),
         data))
     exit(states[state])

puppet/zulip_ops/files/zulip-ec2-configure-interfaces

@@ -131,7 +131,7 @@ for device in macs.values():
     for (count, ip) in enumerate(to_configure):
         # Configure the IP via a virtual interface
         device = "ens%i:%i" % (device_number, count)
-        log.info("Configuring %s with IP %s" % (device, ip))
+        log.info(f"Configuring {device} with IP {ip}")
         subprocess.check_call(['/sbin/ifconfig', device, ip])
         subprocess.check_call(
             ['/sbin/iptables', '-t', 'mangle', '-A', 'OUTPUT', '-m', 'conntrack', '--ctorigdst',

scripts/lib/check_rabbitmq_queue.py

@@ -77,7 +77,7 @@ def analyze_queue_stats(queue_name: str, stats: Dict[str, Any],
         # 50).
         return dict(status=CRITICAL,
                     name=queue_name,
-                    message='queue appears to be stuck, last update %s, queue size %s' % (
+                    message='queue appears to be stuck, last update {}, queue size {}'.format(
                         stats['update_time'], queue_count_rabbitmqctl))
 
     current_size = stats['current_queue_size']
@@ -108,8 +108,7 @@ def analyze_queue_stats(queue_name: str, stats: Dict[str, Any],
 
             return dict(status=status,
                         name=queue_name,
-                        message='clearing the backlog will take too long: %ss, size: %s' % (
+                        message=f'clearing the backlog will take too long: {expected_time_to_clear_backlog}s, size: {current_size}')
-                            expected_time_to_clear_backlog, current_size))
     else:
         # We slept recently, so treat this as a burst.
         if expected_time_to_clear_backlog > MAX_SECONDS_TO_CLEAR_FOR_BURSTS[queue_name]:
@@ -120,8 +119,7 @@ def analyze_queue_stats(queue_name: str, stats: Dict[str, Any],
 
             return dict(status=status,
                         name=queue_name,
-                        message='clearing the burst will take too long: %ss, size: %s' % (
+                        message=f'clearing the burst will take too long: {expected_time_to_clear_backlog}s, size: {current_size}')
-                            expected_time_to_clear_backlog, current_size))
 
     return dict(status=OK,
                 name=queue_name,
@@ -139,10 +137,10 @@ def check_other_queues(queue_counts_dict: Dict[str, int]) -> List[Dict[str, Any]
 
         if count > CRITICAL_COUNT_THRESHOLD_DEFAULT:
             results.append(dict(status=CRITICAL, name=queue,
-                                message='count critical: %s' % (count,)))
+                                message=f'count critical: {count}'))
         elif count > WARN_COUNT_THRESHOLD_DEFAULT:
             results.append(dict(status=WARNING, name=queue,
-                                message='count warning: %s' % (count,)))
+                                message=f'count warning: {count}'))
         else:
             results.append(dict(status=OK, name=queue, message=''))
 
@@ -210,6 +208,6 @@ def check_rabbitmq_queues() -> None:
             queue_error_template.format(result['name'], states[result['status']], result['message'])
             for result in results if result['status'] > 0
         ])
-        print("%s|%s|%s|%s" % (now, status, states[status], error_message))
+        print(f"{now}|{status}|{states[status]}|{error_message}")
     else:
-        print("%s|%s|%s|queues normal" % (now, status, states[status]))
+        print(f"{now}|{status}|{states[status]}|queues normal")

scripts/lib/sharding.py

@@ -15,9 +15,9 @@ setup_path()
 from scripts.lib.zulip_tools import get_config_file
 
 def write_realm_nginx_config_line(f: Any, host: str, port: str) -> None:
-    f.write("""if ($host = '%s') {
+    f.write("""if ($host = '{}') {{
-    set $tornado_server http://tornado%s;
+    set $tornado_server http://tornado{};
-}\n""" % (host, port))
+}}\n""".format(host, port))
 
 # Basic system to do Tornado sharding.  Writes two output .tmp files that need
 # to be renamed to the following files to finalize the changes:
@@ -48,7 +48,7 @@ with open('/etc/zulip/nginx_sharding.conf.tmp', 'w') as nginx_sharding_conf_f, \
                 host = shard
             else:
                 host = f"{shard}.{external_host}"
-            assert host not in shard_map, "host %s duplicated" % (host,)
+            assert host not in shard_map, f"host {host} duplicated"
             shard_map[host] = int(port)
             write_realm_nginx_config_line(nginx_sharding_conf_f, host, port)
         nginx_sharding_conf_f.write('\n')

scripts/lib/unpack-zulip

@@ -14,7 +14,7 @@ from scripts.lib.zulip_tools import DEPLOYMENTS_DIR, FAIL, ENDC, make_deploy_pat
 import version
 
 if len(sys.argv) != 2:
-    print(FAIL + "Usage: %s <tarball>" % (sys.argv[0],) + ENDC)
+    print(FAIL + f"Usage: {sys.argv[0]} <tarball>" + ENDC)
     sys.exit(1)
 
 tarball_path = sys.argv[1]

scripts/lib/upgrade-zulip

@@ -28,12 +28,12 @@ logging.basicConfig(format="%(asctime)s upgrade-zulip: %(message)s",
                     level=logging.INFO)
 
 if len(sys.argv) != 2:
-    print(FAIL + "Usage: %s <tarball>" % (sys.argv[0],) + ENDC)
+    print(FAIL + f"Usage: {sys.argv[0]} <tarball>" + ENDC)
     sys.exit(1)
 
 tarball_path = sys.argv[1]
 
-error_rerun_script = "%s/current/scripts/upgrade-zulip %s" % (DEPLOYMENTS_DIR, tarball_path)
+error_rerun_script = f"{DEPLOYMENTS_DIR}/current/scripts/upgrade-zulip {tarball_path}"
 get_deployment_lock(error_rerun_script)
 
 try:

scripts/lib/upgrade-zulip-from-git

@@ -42,7 +42,7 @@ if args.remote_url:
 os.makedirs(DEPLOYMENTS_DIR, exist_ok=True)
 os.makedirs('/home/zulip/logs', exist_ok=True)
 
-error_rerun_script = "%s/current/scripts/upgrade-zulip-from-git %s" % (DEPLOYMENTS_DIR, refname)
+error_rerun_script = f"{DEPLOYMENTS_DIR}/current/scripts/upgrade-zulip-from-git {refname}"
 get_deployment_lock(error_rerun_script)
 
 try:

scripts/nagios/check-rabbitmq-consumers

@@ -81,7 +81,5 @@ for queue_name in consumers.keys():
     else:
         status = 0
     with open(state_file_tmp, "w") as f:
-        f.write("%s|%s|%s|queue %s has %s consumers, needs %s\n" % (
+        f.write(f"{now}|{status}|{states[status]}|queue {queue_name} has {consumers[queue_name]} consumers, needs {target_count}\n")
-            now, status, states[status], queue_name,
-            consumers[queue_name], target_count))
     os.rename(state_file_tmp, state_file_path)

scripts/nagios/cron_file_helper.py

@@ -32,4 +32,4 @@ def nagios_from_file(results_file: str) -> Tuple[int, str]:
             state = pieces[2]
             data = pieces[3]
 
-    return (ret, "%s: %s" % (state, data))
+    return (ret, f"{state}: {data}")

scripts/restart-server

@@ -66,7 +66,7 @@ if tornado_processes > 1:
         # supervisord group where if any individual process is slow to
         # stop, the whole bundle stays stopped for an extended time.
         logging.info("Restarting Tornado process on port %s", p)
-        subprocess.check_call(["supervisorctl", "restart", "zulip-tornado:port-%s" % (p,)])
+        subprocess.check_call(["supervisorctl", "restart", f"zulip-tornado:port-{p}"])
 else:
     logging.info("Restarting Tornado process")
     subprocess.check_call(["supervisorctl", "restart", "zulip-tornado", "zulip-tornado:*"])

scripts/setup/generate_secrets.py

@@ -82,7 +82,7 @@ def generate_secrets(development: bool = False) -> None:
         return name not in current_conf
 
     def add_secret(name: str, value: str) -> None:
-        lines.append("%s = %s\n" % (name, value))
+        lines.append(f"{name} = {value}\n")
         current_conf[name] = value
 
     for name in AUTOGENERATED_SETTINGS:
@@ -178,7 +178,7 @@ def generate_secrets(development: bool = False) -> None:
         # the end of the file due to human editing.
         f.write("\n" + "".join(lines))
 
-    print("Generated new secrets in %s." % (OUTPUT_SETTINGS_FILENAME,))
+    print(f"Generated new secrets in {OUTPUT_SETTINGS_FILENAME}.")
 
 if __name__ == '__main__':
 

scripts/setup/inline_email_css.py

@@ -78,7 +78,7 @@ def strip_unnecesary_tags(text: str) -> str:
         text = text[start:end]
         return text
     else:
-        raise ValueError("Template does not have %s or %s" % (start_block, end_block))
+        raise ValueError(f"Template does not have {start_block} or {end_block}")
 
 def get_all_templates_from_directory(directory: str) -> Set[str]:
     result = set()

scripts/zulip-puppet-apply

@@ -31,7 +31,7 @@ Exec { path => "/usr/sbin:/usr/bin:/sbin:/bin" }
 """
 
 for pclass in re.split(r'\s*,\s*', config.get('machine', 'puppet_classes')):
-    puppet_config += "include %s\n" % (pclass,)
+    puppet_config += f"include {pclass}\n"
 
 # We use the puppet configuration from the same Zulip checkout as this script
 scripts_path = os.path.join(BASE_DIR, "scripts")

static/assets/favicon/generate

@@ -7,7 +7,7 @@ import subprocess
 # Open the SVG and find the number text elements using XPath
 tree = ET.parse('orig.svg')
 elems = [tree.getroot().findall(
-    ".//*[@id='%s']/{http://www.w3.org/2000/svg}tspan" % (name,))[0]
+    f".//*[@id='{name}']/{{http://www.w3.org/2000/svg}}tspan")[0]
     for name in ('number_back', 'number_front')]
 
 for i in range(1, 100):

tools/check-issue-labels

@@ -64,7 +64,7 @@ def check_issue_labels() -> None:
             if args.force:
                 response = requests.get(next_page_url)
             else:
-                response = requests.get(next_page_url, headers={'Authorization': 'token %s' % (token,)})
+                response = requests.get(next_page_url, headers={'Authorization': f'token {token}'})
             if response.status_code == 401:
                 sys.exit("Error. Please check the token.")
             if response.status_code == 403:

tools/create-test-api-docs

@@ -65,11 +65,11 @@ def create_single_page(pattern: str, out_dir: str, href: str, calls: List[Call])
             }
             </style>
             ''')
-        f.write('<h3>%s</h3>\n' % (html.escape(pattern),))
+        f.write(f'<h3>{html.escape(pattern)}</h3>\n')
         calls.sort(key=lambda call: call['status_code'])
         for call in calls:
             f.write('<hr>')
-            f.write('\n%s' % (fix_test_name(call['test_name']),))
+            f.write('\n{}'.format(fix_test_name(call['test_name'])))
             f.write('<div class="test">')
             try:
                 f.write(call['url'])
@@ -77,7 +77,7 @@ def create_single_page(pattern: str, out_dir: str, href: str, calls: List[Call])
                 f.write(call['url'].encode('utf8'))
             f.write('<br>\n')
             f.write(call['method'] + '<br>\n')
-            f.write('status code: %s<br>\n' % (call['status_code'],))
+            f.write('status code: {}<br>\n'.format(call['status_code']))
             f.write('<br>')
             f.write('</div>')
 
@@ -136,13 +136,13 @@ def create_user_docs() -> None:
             f.write('<ul>\n')
             for pattern in sorted(groups[name]):
                 href = pattern.replace('/', '-') + '.html'
-                link = '<a href="%s">%s</a>' % (href, html.escape(pattern))
+                link = f'<a href="{href}">{html.escape(pattern)}</a>'
                 f.write('<li>' + link + '</li>\n')
                 create_single_page(pattern, out_dir, href, pattern_dict[pattern])
             f.write('</ul>')
             f.write('\n')
 
-    print('open %s' % (main_page,))
+    print(f'open {main_page}')
 
 
 if __name__ == '__main__':

tools/lib/html_branches.py

@@ -190,8 +190,8 @@ def build_id_dict(templates: List[str]) -> (Dict[str, List[str]]):
             list_tags = tokenize(text)
         except FormattedException as e:
             raise Exception('''
-                fn: %s
+                fn: {}
-                %s''' % (fn, e))
+                {}'''.format(fn, e))
 
         for tag in list_tags:
             info = get_tag_info(tag)

tools/lib/provision_inner.py

@@ -276,7 +276,7 @@ def main(options: argparse.Namespace) -> int:
 
         destroyed = destroy_leaked_test_databases()
         if destroyed:
-            print("Dropped %s stale test databases!" % (destroyed,))
+            print(f"Dropped {destroyed} stale test databases!")
 
     clean_unused_caches()
 
@@ -304,7 +304,7 @@ def main(options: argparse.Namespace) -> int:
             pass
 
     version_file = os.path.join(UUID_VAR_PATH, 'provision_version')
-    print('writing to %s\n' % (version_file,))
+    print(f'writing to {version_file}\n')
     open(version_file, 'w').write(PROVISION_VERSION + '\n')
 
     print()

tools/lib/sanity_check.py

@@ -11,7 +11,7 @@ def check_venv(filename: str) -> None:
         ujson
         zulip
     except ImportError:
-        print("You need to run %s inside a Zulip dev environment." % (filename,))
+        print(f"You need to run {filename} inside a Zulip dev environment.")
         user_id = os.getuid()
         user_name = pwd.getpwuid(user_id).pw_name
         if user_name != 'vagrant' and user_name != 'zulipdev':

tools/lib/template_parser.py

@@ -213,8 +213,8 @@ def validate(fn: Optional[str] = None, text: Optional[str] = None, check_indent:
         tokens = tokenize(text)
     except FormattedException as e:
         raise TemplateParserException('''
-            fn: %s
+            fn: {}
-            %s''' % (fn, e))
+            {}'''.format(fn, e))
 
     class State:
         def __init__(self, func: Callable[[Token], None]) -> None:

tools/lib/test_server.py

@@ -37,7 +37,7 @@ def assert_server_running(server: "subprocess.Popen[bytes]", log_file: Optional[
     if server.poll() is not None:
         message = 'Server died unexpectedly!'
         if log_file:
-            message += '\nSee %s\n' % (log_file,)
+            message += f'\nSee {log_file}\n'
         raise RuntimeError(message)
 
 def server_is_up(server: "subprocess.Popen[bytes]", log_file: Optional[str]) -> bool:

tools/pretty-print-html

@@ -5,7 +5,7 @@ import sys
 
 def clean_html(filenames: List[str]) -> None:
     for fn in filenames:
-        print('Prettifying: %s' % (fn,))
+        print(f'Prettifying: {fn}')
         with open(fn) as f:
             html = f.read()
         phtml = pretty_print_html(html)

tools/review

@@ -31,14 +31,14 @@ def check_git_pristine() -> None:
 def ensure_on_clean_master() -> None:
     branch = get_git_branch()
     if branch != 'master':
-        exit('You are still on a feature branch: %s' % (branch,))
+        exit(f'You are still on a feature branch: {branch}')
     check_git_pristine()
     run(['git', 'fetch', 'upstream', 'master'])
     run(['git', 'rebase', 'upstream/master'])
 
 def create_pull_branch(pull_id: int) -> None:
     run(['git', 'fetch', 'upstream', 'pull/%d/head' % (pull_id,)])
-    run(['git', 'checkout', '-B', 'review-%s' % (pull_id,), 'FETCH_HEAD'])
+    run(['git', 'checkout', '-B', f'review-{pull_id}', 'FETCH_HEAD'])
     run(['git', 'rebase', 'upstream/master'])
     run(['git', 'log', 'upstream/master..', '--oneline'])
     run(['git', 'diff', 'upstream/master..', '--name-status'])

tools/run-dev.py

@@ -98,7 +98,7 @@ if options.test:
 else:
     settings_module = "zproject.settings"
 
-manage_args = ['--settings=%s' % (settings_module,)]
+manage_args = [f'--settings={settings_module}']
 os.environ['DJANGO_SETTINGS_MODULE'] = settings_module
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
@@ -158,7 +158,7 @@ def server_processes() -> List[List[str]]:
          './puppet/zulip/files/postgresql/process_fts_updates', '--quiet'],
         ['./manage.py', 'deliver_scheduled_messages'],
         ['/srv/zulip-thumbor-venv/bin/thumbor', '-c', './zthumbor/thumbor.conf',
-         '-p', '%s' % (thumbor_port,)],
+         '-p', f'{thumbor_port}'],
     ]
 
     # NORMAL (but slower) operation:

tools/setup/emoji/build_emoji

@@ -79,7 +79,7 @@ def main() -> None:
         # anyway, because EMOJI_CACHE_PATH is created by puppet before
         # build_emoji would be run.
         run_as_root(["mkdir", "-p", EMOJI_CACHE_PATH])
-        run_as_root(["chown", "%s:%s" % (os.getuid(), os.getgid()), EMOJI_CACHE_PATH])
+        run_as_root(["chown", f"{os.getuid()}:{os.getgid()}", EMOJI_CACHE_PATH])
 
     sha1_hexdigest = generate_sha1sum_emoji(ZULIP_PATH)
     source_emoji_dump = os.path.join(EMOJI_CACHE_PATH, sha1_hexdigest, 'emoji')
@@ -107,7 +107,7 @@ def main() -> None:
         os.remove(os.path.join(TARGET_EMOJI_STYLES, filename))
 
 def percent(f: float) -> str:
-    return '%0.3f%%' % (f * 100,)
+    return f'{f * 100:0.3f}%'
 
 def get_square_size(emoji_data: List[Dict[str, Any]]) -> int:
     """
@@ -207,7 +207,7 @@ def generate_sprite_css_files(cache_path: str,
                 'pos_y': percent(emoji["sheet_y"] / (n - 1)),
             }
 
-    SPRITE_CSS_PATH = os.path.join(cache_path, '%s-sprite.css' % (emojiset,))
+    SPRITE_CSS_PATH = os.path.join(cache_path, f'{emojiset}-sprite.css')
     with open(SPRITE_CSS_PATH, 'w') as f:
         f.write(SPRITE_CSS_FILE_TEMPLATE % {'emojiset': emojiset,
                                             'alt_name': alt_name,

tools/setup/emoji/import_emoji_names_from_csv

@@ -47,12 +47,12 @@ def load_data(data_file: str) -> List[List[str]]:
 
 def check_uniqueness(emoji_name: str) -> None:
     if emoji_name in emoji_names:
-        raise Exception("Duplicate emoji name: %s" % (emoji_name,))
+        raise Exception(f"Duplicate emoji name: {emoji_name}")
     emoji_names.add(emoji_name)
 
 def check_valid_emoji_name(emoji_name: str) -> None:
     if re.fullmatch("[+-]?[a-z0-9_-]+", emoji_name) is None:
-        raise Exception("Invalid emoji name: %s" % (emoji_name,))
+        raise Exception(f"Invalid emoji name: {emoji_name}")
 
 def check_emoji_names(canonical_name: str, aliases: List[str]) -> None:
     if canonical_name == 'X':

tools/test-backend

@@ -314,7 +314,7 @@ def main() -> None:
                 classname = suite.rsplit('.', 1)[0]
                 rewrite_arguments(classname)
             elif suite[0].isupper():
-                rewrite_arguments('class %s(' % (suite,))
+                rewrite_arguments(f'class {suite}(')
 
         for i, suite in enumerate(args):
             if suite.startswith('test'):
@@ -403,7 +403,7 @@ def main() -> None:
     # We only check the templates if all the tests ran and passed
     if not failures and full_suite and templates_not_rendered:
         missed_count = len(templates_not_rendered)
-        print("\nError: %s templates have no tests!" % (missed_count,))
+        print(f"\nError: {missed_count} templates have no tests!")
         for template in templates_not_rendered:
             print(f'  {template}')
         print("See zerver/tests/test_templates.py for the exclude list.")
@@ -424,8 +424,8 @@ def main() -> None:
         for path in enforce_fully_covered:
             missing_lines = cov.analysis2(path)[3]
             if len(missing_lines) > 0:
-                print("ERROR: %s no longer has complete backend test coverage" % (path,))
+                print(f"ERROR: {path} no longer has complete backend test coverage")
-                print("  Lines missing coverage: %s" % (missing_lines,))
+                print(f"  Lines missing coverage: {missing_lines}")
                 print()
                 failures = True
         if failures:
@@ -439,7 +439,7 @@ def main() -> None:
             try:
                 missing_lines = cov.analysis2(path)[3]
                 if len(missing_lines) == 0 and path != "zerver/lib/migrate.py":
-                    print("ERROR: %s has complete backend test coverage but is still in not_yet_fully_covered." % (path,))
+                    print(f"ERROR: {path} has complete backend test coverage but is still in not_yet_fully_covered.")
                     ok = False
             except coverage.misc.NoSource:
                 continue
@@ -471,7 +471,7 @@ def main() -> None:
 
     removed = remove_test_run_directories()
     if removed:
-        print("Removed %s stale test run directories!" % (removed,))
+        print(f"Removed {removed} stale test run directories!")
 
     # We'll have printed whether tests passed or failed above
     sys.exit(bool(failures))

tools/test-js-with-node

@@ -242,7 +242,7 @@ def run_tests_via_node_js() -> int:
     try:
         ret = subprocess.check_call(command)
     except OSError:
-        print('Bad command: %s' % (command,))
+        print(f'Bad command: {command}')
         raise
     except subprocess.CalledProcessError:
         print('\n** Tests failed, PLEASE FIX! **\n')
@@ -257,8 +257,8 @@ def check_line_coverage(fn: str, line_coverage: Dict[Any, Any], line_mapping: Di
             missing_lines.append(str(actual_line["start"]["line"]))
     if missing_lines:
         if log:
-            print_error("%s no longer has complete node test coverage" % (fn,))
+            print_error(f"{fn} no longer has complete node test coverage")
-            print("  Lines missing coverage: %s" % (", ".join(sorted(missing_lines, key=int)),))
+            print("  Lines missing coverage: {}".format(", ".join(sorted(missing_lines, key=int))))
             print()
         return False
     return True
@@ -288,7 +288,7 @@ def enforce_proper_coverage(coverage_json: Any) -> bool:
         path = ROOT_DIR + "/" + relative_path
         if not (path in coverage_json):
             coverage_lost = True
-            print_error("%s has no node test coverage" % (relative_path,))
+            print_error(f"{relative_path} has no node test coverage")
             continue
         line_coverage = coverage_json[path]['s']
         line_mapping = coverage_json[path]['statementMap']

tools/test-js-with-puppeteer

@@ -58,7 +58,7 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
         for test_file in test_files:
             test_name = os.path.basename(test_file)
             cmd = ["node"] + [test_file]
-            print("\n\n===================== %s\nRunning %s\n\n" % (test_name, " ".join(map(shlex.quote, cmd))), flush=True)
+            print("\n\n===================== {}\nRunning {}\n\n".format(test_name, " ".join(map(shlex.quote, cmd))), flush=True)
             ret = subprocess.call(cmd)
             if ret != 0:
                 return ret

tools/tests/test_html_branches.py

@@ -108,14 +108,14 @@ class TestHtmlBranches(unittest.TestCase):
 
         self.assertEqual(set(template_id_dict.keys()), {'below_navbar', 'hello_{{ message }}', 'intro'})
         self.assertEqual(template_id_dict['hello_{{ message }}'], [
-                         'Line 12:%s/tools/tests/test_template_data/test_template1.html' % (ZULIP_PATH,),
+                         f'Line 12:{ZULIP_PATH}/tools/tests/test_template_data/test_template1.html',
-                         'Line 12:%s/tools/tests/test_template_data/test_template2.html' % (ZULIP_PATH,)])
+                         f'Line 12:{ZULIP_PATH}/tools/tests/test_template_data/test_template2.html'])
         self.assertEqual(template_id_dict['intro'], [
-                         'Line 10:%s/tools/tests/test_template_data/test_template1.html' % (ZULIP_PATH,),
+                         f'Line 10:{ZULIP_PATH}/tools/tests/test_template_data/test_template1.html',
-                         'Line 11:%s/tools/tests/test_template_data/test_template1.html' % (ZULIP_PATH,),
+                         f'Line 11:{ZULIP_PATH}/tools/tests/test_template_data/test_template1.html',
-                         'Line 11:%s/tools/tests/test_template_data/test_template2.html' % (ZULIP_PATH,)])
+                         f'Line 11:{ZULIP_PATH}/tools/tests/test_template_data/test_template2.html'])
         self.assertEqual(template_id_dict['below_navbar'], [
-                         'Line 10:%s/tools/tests/test_template_data/test_template2.html' % (ZULIP_PATH,)])
+                         f'Line 10:{ZULIP_PATH}/tools/tests/test_template_data/test_template2.html'])
 
     def test_split_for_id_and_class(self) -> None:
         id1 = "{{ red|blue }}"

tools/update-zuliprc-api-field

@@ -65,11 +65,11 @@ for zuliprc_path in zuliprc_paths_list:
                 with open(zuliprc_path, 'w+') as w:
                     zuliprc.write(w)
                 result = 'SUCCESS'
-                reason = 'API field updated for user %s' % (email,)
+                reason = f'API field updated for user {email}'
             except OSError:
                 result = 'FAILURE'
                 reason = 'Writing to file unsuccessful'
         else:
             result = 'SUCCESS'
-            reason = 'API key for user %s is already consistent' % (email,)
+            reason = f'API key for user {email} is already consistent'
     print(f'{zuliprc_path}: {result}: {reason}')

tools/webpack

@@ -97,9 +97,9 @@ def build_for_most_tests() -> None:
     with open('tools/webpack.assets.json') as json_data:
         for entry in json.load(json_data).keys():
             entries[entry] = [{
-                "name": "%s.js" % (entry,),
+                "name": f"{entry}.js",
-                "publicPath": "http://localhost:3000/webpack-stub/%s-stubentry.js" % (entry,),
+                "publicPath": f"http://localhost:3000/webpack-stub/{entry}-stubentry.js",
-                "path": "/stubfolder/%s-stubfile.js" % (entry,)
+                "path": f"/stubfolder/{entry}-stubfile.js"
             }]
     stat_data = {
         "status": "done",

tools/zulip-export/zulip-export

@@ -81,7 +81,7 @@ for msg in result['messages']:
         msg.pop(k, None)
     messages.append(msg)
 
-filename = "zulip-%s.json" % (options.stream,)
+filename = f"zulip-{options.stream}.json"
 with open(filename, 'wb') as f:
     f.write(json.dumps(messages, indent=0, sort_keys=False).encode('utf-8'))
 print("%d messages exported to %s" % (len(messages), filename,))

zerver/context_processors.py

@@ -141,7 +141,7 @@ def zulip_default_context(request: HttpRequest) -> Dict[str, Any]:
         'landing_page_navbar_message': settings.LANDING_PAGE_NAVBAR_MESSAGE,
     }
 
-    context['OPEN_GRAPH_URL'] = '%s%s' % (realm_uri, request.path)
+    context['OPEN_GRAPH_URL'] = f'{realm_uri}{request.path}'
     if realm is not None and realm.icon_source == realm.ICON_UPLOADED:
         context['OPEN_GRAPH_IMAGE'] = urljoin(realm_uri, realm_icon)
 
@@ -175,7 +175,7 @@ def login_context(request: HttpRequest) -> Dict[str, Any]:
     no_auth_enabled = True
     for auth_backend_name in AUTH_BACKEND_NAME_MAP:
         name_lower = auth_backend_name.lower()
-        key = "%s_auth_enabled" % (name_lower,)
+        key = f"{name_lower}_auth_enabled"
         is_enabled = auth_enabled_helper([auth_backend_name], realm)
         context[key] = is_enabled
         if is_enabled:
@@ -191,7 +191,7 @@ def login_context(request: HttpRequest) -> Dict[str, Any]:
         external_authentication_methods = get_external_method_dicts(realm)
     )
     for auth_dict in context['page_params']['external_authentication_methods']:
-        auth_dict['button_id_suffix'] = "auth_button_%s" % (auth_dict['name'],)
+        auth_dict['button_id_suffix'] = "auth_button_{}".format(auth_dict['name'])
 
     return context
 

zerver/data_import/gitter.py

@@ -97,7 +97,7 @@ def build_userprofile(timestamp: Any, domain_name: str,
 
 def get_user_email(user_data: ZerverFieldsT, domain_name: str) -> str:
     # TODO Get user email from github
-    email = ("%s@users.noreply.github.com" % (user_data['username'],))
+    email = ("{}@users.noreply.github.com".format(user_data['username']))
     return email
 
 def build_stream_map(timestamp: Any,
@@ -240,14 +240,14 @@ def get_usermentions(message: Dict[str, Any], user_map: Dict[str, int],
     if 'mentions' in message:
         for mention in message['mentions']:
             if mention.get('userId') in user_map:
-                gitter_mention = '@%s' % (mention['screenName'],)
+                gitter_mention = '@{}'.format(mention['screenName'])
                 if mention['screenName'] not in user_short_name_to_full_name:
                     logging.info("Mentioned user %s never sent any messages, so has no full name data",
                                  mention['screenName'])
                     full_name = mention['screenName']
                 else:
                     full_name = user_short_name_to_full_name[mention['screenName']]
-                zulip_mention = ('@**%s**' % (full_name,))
+                zulip_mention = (f'@**{full_name}**')
                 message['text'] = message['text'].replace(gitter_mention, zulip_mention)
 
                 mentioned_user_ids.append(user_map[mention['userId']])

zerver/data_import/import_util.py

@@ -50,7 +50,7 @@ def build_zerver_realm(realm_id: int, realm_subdomain: str, time: float,
                        other_product: str) -> List[ZerverFieldsT]:
     realm = Realm(id=realm_id, date_created=time,
                   name=realm_subdomain, string_id=realm_subdomain,
-                  description="Organization imported from %s!" % (other_product,))
+                  description=f"Organization imported from {other_product}!")
     auth_methods = [[flag[0], flag[1]] for flag in realm.authentication_methods]
     realm_dict = model_to_dict(realm, exclude='authentication_methods')
     realm_dict['authentication_methods'] = auth_methods
@@ -514,8 +514,8 @@ def process_avatars(avatar_list: List[ZerverFieldsT], avatar_dir: str, realm_id:
         avatar_url = avatar['path']
         avatar_original = dict(avatar)
 
-        image_path = '%s.png' % (avatar_hash,)
+        image_path = f'{avatar_hash}.png'
-        original_image_path = '%s.original' % (avatar_hash,)
+        original_image_path = f'{avatar_hash}.original'
 
         avatar_upload_list.append([avatar_url, image_path, original_image_path])
         # We don't add the size field here in avatar's records.json,

zerver/data_import/slack.py

@@ -227,7 +227,7 @@ def build_customprofile_field(customprofile_field: List[ZerverFieldsT], fields:
             if field in slack_custom_fields:
                 field_name = field
             else:
-                field_name = "slack custom field %s" % (str(custom_profile_field_id + 1),)
+                field_name = f"slack custom field {str(custom_profile_field_id + 1)}"
             customprofilefield = CustomProfileField(
                 id=custom_profile_field_id,
                 name=field_name,
@@ -294,10 +294,10 @@ def get_user_email(user: ZerverFieldsT, domain_name: str) -> str:
             slack_bot_name = user['profile']['first_name']
         else:
             raise AssertionError("Could not identify bot type")
-        return slack_bot_name.replace("Bot", "").replace(" ", "") + "-bot@%s" % (domain_name,)
+        return slack_bot_name.replace("Bot", "").replace(" ", "") + f"-bot@{domain_name}"
     if get_user_full_name(user).lower() == "slackbot":
-        return "imported-slackbot-bot@%s" % (domain_name,)
+        return f"imported-slackbot-bot@{domain_name}"
-    raise AssertionError("Could not find email address for Slack user %s" % (user,))
+    raise AssertionError(f"Could not find email address for Slack user {user}")
 
 def build_avatar_url(slack_user_id: str, team_id: str, avatar_hash: str) -> str:
     avatar_url = f"https://ca.slack-edge.com/{team_id}-{slack_user_id}-{avatar_hash}"
@@ -742,7 +742,7 @@ def channel_message_to_zerver_message(realm_id: int,
         # For example "sh_room_created" has the message 'started a call'
         # which should be displayed as '/me started a call'
         if subtype in ["bot_add", "sh_room_created", "me_message"]:
-            content = '/me %s' % (content,)
+            content = f'/me {content}'
         if subtype == 'file_comment':
             # The file_comment message type only indicates the
             # responsible user in a subfield.
@@ -864,7 +864,7 @@ def process_message_files(message: ZerverFieldsT,
                 file_name = fileinfo['title']
             else:
                 file_name = fileinfo['name']
-            markdown_links.append('[%s](%s)' % (file_name, fileinfo['url_private']))
+            markdown_links.append('[{}]({})'.format(file_name, fileinfo['url_private']))
 
     content = '\n'.join(markdown_links)
 
@@ -887,8 +887,8 @@ def get_attachment_path_and_content(fileinfo: ZerverFieldsT, realm_id: int) -> T
         random_name(18),
         sanitize_name(fileinfo['name'])
     ])
-    attachment_path = '/user_uploads/%s' % (s3_path,)
+    attachment_path = f'/user_uploads/{s3_path}'
-    content = '[%s](%s)' % (fileinfo['title'], attachment_path)
+    content = '[{}]({})'.format(fileinfo['title'], attachment_path)
 
     return s3_path, content
 
@@ -1119,7 +1119,7 @@ def get_slack_api_data(slack_api_url: str, get_param: str, **kwargs: Any) -> Any
     if data.status_code == requests.codes.ok:
         result = data.json()
         if not result['ok']:
-            raise Exception('Error accessing Slack API: %s' % (result['error'],))
+            raise Exception('Error accessing Slack API: {}'.format(result['error']))
         return result[get_param]
 
     raise Exception('HTTP error accessing the Slack API.')

zerver/data_import/slack_message_conversion.py

@@ -85,7 +85,7 @@ def convert_to_zulip_markdown(text: str, users: List[ZerverFieldsT],
     # Map Slack channel mention: '<#C5Z73A7RA|general>' to '#**general**'
     for cname, ids in added_channels.items():
         cid = ids[0]
-        text = text.replace('<#%s|%s>' % (cid, cname), '#**' + cname + '**')
+        text = text.replace(f'<#{cid}|{cname}>', '#**' + cname + '**')
 
     tokens = text.split(' ')
     for iterator in range(len(tokens)):

zerver/forms.py

@@ -57,7 +57,7 @@ def email_is_not_mit_mailing_list(email: str) -> None:
         username = email.rsplit("@", 1)[0]
         # Check whether the user exists and can get mail.
         try:
-            DNS.dnslookup("%s.pobox.ns.athena.mit.edu" % (username,), DNS.Type.TXT)
+            DNS.dnslookup(f"{username}.pobox.ns.athena.mit.edu", DNS.Type.TXT)
         except DNS.Base.ServerError as e:
             if e.rcode == DNS.Status.NXDOMAIN:
                 raise ValidationError(mark_safe(MIT_VALIDATION_ERROR))

zerver/lib/actions.py

@@ -394,10 +394,7 @@ def process_new_human_user(user_profile: UserProfile,
             user_profile.realm,
             get_system_bot(settings.NOTIFICATION_BOT),
             prereg_user.referred_by,
-            "%s <`%s`> accepted your invitation to join Zulip!" % (
+            f"{user_profile.full_name} <`{user_profile.email}`> accepted your invitation to join Zulip!"
-                user_profile.full_name,
-                user_profile.email,
-            )
         )
     # Mark any other PreregistrationUsers that are STATUS_ACTIVE as
     # inactive so we can keep track of the PreregistrationUser we
@@ -598,8 +595,7 @@ def do_set_realm_property(realm: Realm, name: str, value: Any) -> None:
     """
     property_type = Realm.property_types[name]
     assert isinstance(value, property_type), (
-        'Cannot update %s: %s is not an instance of %s' % (
+        f'Cannot update {name}: {value} is not an instance of {property_type}')
-            name, value, property_type,))
 
     old_value = getattr(realm, name)
     setattr(realm, name, value)
@@ -2359,8 +2355,7 @@ def _internal_prep_message(realm: Realm,
         return check_message(sender, get_client("Internal"), addressee,
                              content, realm=realm)
     except JsonableError as e:
-        logging.exception("Error queueing internal message by %s: %s" % (
+        logging.exception(f"Error queueing internal message by {sender.delivery_email}: {e}")
-            sender.delivery_email, e))
 
     return None
 
@@ -3587,7 +3582,7 @@ def do_change_stream_description(stream: Stream, new_description: str) -> None:
 def do_create_realm(string_id: str, name: str,
                     emails_restricted_to_domains: Optional[bool]=None) -> Realm:
     if Realm.objects.filter(string_id=string_id).exists():
-        raise AssertionError("Realm %s already exists!" % (string_id,))
+        raise AssertionError(f"Realm {string_id} already exists!")
     if not server_initialized():
         logging.info("Server not yet initialized. Creating the internal realm first.")
         create_internal_realm()
@@ -3653,8 +3648,7 @@ def do_change_notification_settings(user_profile: UserProfile, name: str,
 
     notification_setting_type = UserProfile.notification_setting_types[name]
     assert isinstance(value, notification_setting_type), (
-        'Cannot update %s: %s is not an instance of %s' % (
+        f'Cannot update {name}: {value} is not an instance of {notification_setting_type}')
-            name, value, notification_setting_type,))
 
     setattr(user_profile, name, value)
 
@@ -4179,7 +4173,7 @@ def do_update_message_flags(user_profile: UserProfile,
     if flag == "read" and operation == "add":
         do_clear_mobile_push_notifications_for_ids(user_profile, messages)
 
-    statsd.incr("flags.%s.%s" % (flag, operation), count)
+    statsd.incr(f"flags.{flag}.{operation}", count)
     return count
 
 class MessageUpdateUserInfoResult(TypedDict):
@@ -4199,9 +4193,9 @@ def notify_topic_moved_streams(user_profile: UserProfile,
     if new_topic is None:
         new_topic = old_topic
 
-    user_mention = "@_**%s|%s**" % (user_profile.full_name, user_profile.id)
+    user_mention = f"@_**{user_profile.full_name}|{user_profile.id}**"
-    old_topic_link = "#**%s>%s**" % (old_stream.name, old_topic)
+    old_topic_link = f"#**{old_stream.name}>{old_topic}**"
-    new_topic_link = "#**%s>%s**" % (new_stream.name, new_topic)
+    new_topic_link = f"#**{new_stream.name}>{new_topic}**"
     if send_notification_to_new_thread:
         internal_send_stream_message(
             new_stream.realm, sender, new_stream, new_topic,
@@ -4918,7 +4912,7 @@ def do_send_confirmation_email(invitee: PreregistrationUser,
     activation_url = create_confirmation_link(invitee, referrer.realm.host, Confirmation.INVITATION)
     context = {'referrer_full_name': referrer.full_name, 'referrer_email': referrer.delivery_email,
                'activate_url': activation_url, 'referrer_realm_name': referrer.realm.name}
-    from_name = "%s (via Zulip)" % (referrer.full_name,)
+    from_name = f"{referrer.full_name} (via Zulip)"
     send_email('zerver/emails/invitation', to_emails=[invitee.email], from_name=from_name,
                from_address=FromAddress.tokenized_no_reply_address(),
                language=referrer.realm.default_language, context=context)

zerver/lib/avatar.py

@@ -92,9 +92,9 @@ def get_gravatar_url(email: str, avatar_version: int, medium: bool=False) -> str
 
 def _get_unversioned_gravatar_url(email: str, medium: bool) -> str:
     if settings.ENABLE_GRAVATAR:
-        gravitar_query_suffix = "&s=%s" % (MEDIUM_AVATAR_SIZE,) if medium else ""
+        gravitar_query_suffix = f"&s={MEDIUM_AVATAR_SIZE}" if medium else ""
         hash_key = gravatar_hash(email)
-        return "https://secure.gravatar.com/avatar/%s?d=identicon%s" % (hash_key, gravitar_query_suffix)
+        return f"https://secure.gravatar.com/avatar/{hash_key}?d=identicon{gravitar_query_suffix}"
     return settings.DEFAULT_AVATAR_URI+'?x=x'
 
 def _get_unversioned_avatar_url(user_profile_id: int,

zerver/lib/avatar_hash.py

@@ -34,7 +34,7 @@ def user_avatar_path(user_profile: UserProfile) -> str:
 
 def user_avatar_path_from_ids(user_profile_id: int, realm_id: int) -> str:
     user_id_hash = user_avatar_hash(str(user_profile_id))
-    return '%s/%s' % (str(realm_id), user_id_hash)
+    return f'{str(realm_id)}/{user_id_hash}'
 
 def user_avatar_content_hash(ldap_avatar: bytes) -> str:
     return hashlib.sha256(ldap_avatar).hexdigest()

zerver/lib/bot_lib.py

@@ -27,7 +27,7 @@ def get_bot_handler(service_name: str) -> Any:
             configured_service = embedded_bot_service.name
     if not configured_service:
         return None
-    bot_module_name = 'zulip_bots.bots.%s.%s' % (configured_service, configured_service)
+    bot_module_name = f'zulip_bots.bots.{configured_service}.{configured_service}'
     bot_module: Any = importlib.import_module(bot_module_name)
     return bot_module.handler_class()
 

zerver/lib/bugdown/help_relative_links.py

@@ -34,9 +34,9 @@ gear_instructions = """
 
 def gear_handle_match(key: str) -> str:
     if relative_help_links:
-        item = '[%s](%s)' % (gear_info[key][0], gear_info[key][1])
+        item = f'[{gear_info[key][0]}]({gear_info[key][1]})'
     else:
-        item = '**%s**' % (gear_info[key][0],)
+        item = f'**{gear_info[key][0]}**'
     return gear_instructions % {'item': item}
 
 
@@ -54,7 +54,7 @@ stream_instructions_no_link = """
 
 def stream_handle_match(key: str) -> str:
     if relative_help_links:
-        return "1. Go to [%s](%s)." % (stream_info[key][0], stream_info[key][1])
+        return f"1. Go to [{stream_info[key][0]}]({stream_info[key][1]})."
     if key == 'all':
         return stream_instructions_no_link + "\n\n1. Click **All streams** in the upper left."
     return stream_instructions_no_link

zerver/lib/bugdown/help_settings_links.py

@@ -103,9 +103,9 @@ class Setting(Preprocessor):
         setting_name = link_mapping[setting_identifier][1]
         setting_link = link_mapping[setting_identifier][2]
         if relative_settings_links:
-            return "1. Go to [%s](%s)." % (setting_name, setting_link)
+            return f"1. Go to [{setting_name}]({setting_link})."
         return settings_markdown % {'setting_type_name': setting_type_name,
-                                    'setting_reference': "**%s**" % (setting_name,)}
+                                    'setting_reference': f"**{setting_name}**"}
 
 def makeExtension(*args: Any, **kwargs: Any) -> SettingHelpExtension:
     return SettingHelpExtension(*args, **kwargs)

zerver/lib/cache.py

@@ -176,7 +176,7 @@ def cache_with_key(
                 metric_key = statsd_key(key)
 
             status = "hit" if val is not None else "miss"
-            statsd.incr("cache%s.%s.%s" % (extra, metric_key, status))
+            statsd.incr(f"cache{extra}.{metric_key}.{status}")
 
             # Values are singleton tuples so that we can distinguish
             # a result of None from a missing key.
@@ -409,7 +409,7 @@ def generic_bulk_cached_fetch(
             if cache_keys[object_id] in cached_objects}
 
 def preview_url_cache_key(url: str) -> str:
-    return "preview_url:%s" % (make_safe_digest(url),)
+    return f"preview_url:{make_safe_digest(url)}"
 
 def display_recipient_cache_key(recipient_id: int) -> str:
     return "display_recipient_dict:%d" % (recipient_id,)
@@ -423,22 +423,22 @@ def user_profile_by_email_cache_key(email: str) -> str:
     # See the comment in zerver/lib/avatar_hash.py:gravatar_hash for why we
     # are proactively encoding email addresses even though they will
     # with high likelihood be ASCII-only for the foreseeable future.
-    return 'user_profile_by_email:%s' % (make_safe_digest(email.strip()),)
+    return f'user_profile_by_email:{make_safe_digest(email.strip())}'
 
 def user_profile_cache_key_id(email: str, realm_id: int) -> str:
-    return "user_profile:%s:%s" % (make_safe_digest(email.strip()), realm_id,)
+    return f"user_profile:{make_safe_digest(email.strip())}:{realm_id}"
 
 def user_profile_cache_key(email: str, realm: 'Realm') -> str:
     return user_profile_cache_key_id(email, realm.id)
 
 def bot_profile_cache_key(email: str) -> str:
-    return "bot_profile:%s" % (make_safe_digest(email.strip()),)
+    return f"bot_profile:{make_safe_digest(email.strip())}"
 
 def user_profile_by_id_cache_key(user_profile_id: int) -> str:
-    return "user_profile_by_id:%s" % (user_profile_id,)
+    return f"user_profile_by_id:{user_profile_id}"
 
 def user_profile_by_api_key_cache_key(api_key: str) -> str:
-    return "user_profile_by_api_key:%s" % (api_key,)
+    return f"user_profile_by_api_key:{api_key}"
 
 realm_user_dict_fields: List[str] = [
     'id', 'full_name', 'short_name', 'email',
@@ -449,16 +449,16 @@ realm_user_dict_fields: List[str] = [
 ]
 
 def realm_user_dicts_cache_key(realm_id: int) -> str:
-    return "realm_user_dicts:%s" % (realm_id,)
+    return f"realm_user_dicts:{realm_id}"
 
 def get_realm_used_upload_space_cache_key(realm: 'Realm') -> str:
-    return 'realm_used_upload_space:%s' % (realm.id,)
+    return f'realm_used_upload_space:{realm.id}'
 
 def active_user_ids_cache_key(realm_id: int) -> str:
-    return "active_user_ids:%s" % (realm_id,)
+    return f"active_user_ids:{realm_id}"
 
 def active_non_guest_user_ids_cache_key(realm_id: int) -> str:
-    return "active_non_guest_user_ids:%s" % (realm_id,)
+    return f"active_non_guest_user_ids:{realm_id}"
 
 bot_dict_fields: List[str] = [
     'api_key',
@@ -478,11 +478,10 @@ bot_dict_fields: List[str] = [
 ]
 
 def bot_dicts_in_realm_cache_key(realm: 'Realm') -> str:
-    return "bot_dicts_in_realm:%s" % (realm.id,)
+    return f"bot_dicts_in_realm:{realm.id}"
 
 def get_stream_cache_key(stream_name: str, realm_id: int) -> str:
-    return "stream_by_realm_and_name:%s:%s" % (
+    return f"stream_by_realm_and_name:{realm_id}:{make_safe_digest(stream_name.strip().lower())}"
-        realm_id, make_safe_digest(stream_name.strip().lower()))
 
 def delete_user_profile_caches(user_profiles: Iterable['UserProfile']) -> None:
     # Imported here to avoid cyclic dependency.
@@ -571,16 +570,16 @@ def flush_realm(sender: Any, **kwargs: Any) -> None:
         cache_delete(realm_text_description_cache_key(realm))
 
 def realm_alert_words_cache_key(realm: 'Realm') -> str:
-    return "realm_alert_words:%s" % (realm.string_id,)
+    return f"realm_alert_words:{realm.string_id}"
 
 def realm_alert_words_automaton_cache_key(realm: 'Realm') -> str:
-    return "realm_alert_words_automaton:%s" % (realm.string_id,)
+    return f"realm_alert_words_automaton:{realm.string_id}"
 
 def realm_rendered_description_cache_key(realm: 'Realm') -> str:
-    return "realm_rendered_description:%s" % (realm.string_id,)
+    return f"realm_rendered_description:{realm.string_id}"
 
 def realm_text_description_cache_key(realm: 'Realm') -> str:
-    return "realm_text_description:%s" % (realm.string_id,)
+    return f"realm_text_description:{realm.string_id}"
 
 # Called by models.py to flush the stream cache whenever we save a stream
 # object.
@@ -610,7 +609,7 @@ def to_dict_cache_key(message: 'Message', realm_id: Optional[int]=None) -> str:
     return to_dict_cache_key_id(message.id)
 
 def open_graph_description_cache_key(content: Any, request: HttpRequest) -> str:
-    return 'open_graph_description_path:%s' % (make_safe_digest(request.META['PATH_INFO']),)
+    return 'open_graph_description_path:{}'.format(make_safe_digest(request.META['PATH_INFO']))
 
 def flush_message(sender: Any, **kwargs: Any) -> None:
     message = kwargs['instance']

zerver/lib/camo.py

@@ -8,7 +8,7 @@ def generate_camo_url(url: str) -> str:
     encoded_camo_key = settings.CAMO_KEY.encode("utf-8")
     digest = hmac.new(encoded_camo_key, encoded_url, hashlib.sha1).hexdigest()
     hex_encoded_url = binascii.b2a_hex(encoded_url)
-    return "%s/%s" % (digest, hex_encoded_url.decode("utf-8"))
+    return "{}/{}".format(digest, hex_encoded_url.decode("utf-8"))
 
 # Encodes the provided URL using the same algorithm used by the camo
 # caching https image proxy
@@ -16,7 +16,7 @@ def get_camo_url(url: str) -> str:
     # Only encode the url if Camo is enabled
     if settings.CAMO_URI == '':
         return url
-    return "%s%s" % (settings.CAMO_URI, generate_camo_url(url))
+    return f"{settings.CAMO_URI}{generate_camo_url(url)}"
 
 def is_camo_url_valid(digest: str, url: str) -> bool:
     camo_url = generate_camo_url(url)

zerver/lib/create_user.py

@@ -33,7 +33,7 @@ def copy_user_settings(source_profile: UserProfile, target_profile: UserProfile)
 
 def get_display_email_address(user_profile: UserProfile, realm: Realm) -> str:
     if not user_profile.email_address_is_realm_public():
-        return "user%s@%s" % (user_profile.id, get_fake_email_domain())
+        return f"user{user_profile.id}@{get_fake_email_domain()}"
     return user_profile.delivery_email
 
 def get_role_for_new_user(invited_as: int, realm_creation: bool=False) -> int:

zerver/lib/db.py

@@ -23,7 +23,7 @@ def wrapper_execute(self: CursorObj,
         stop = time.time()
         duration = stop - start
         self.connection.queries.append({
-            'time': "%.3f" % (duration,),
+            'time': f"{duration:.3f}",
         })
 
 class TimeTrackingCursor(cursor):

zerver/lib/digest.py

@@ -146,14 +146,14 @@ def gather_new_streams(user_profile: UserProfile,
     else:
         new_streams = []
 
-    base_url = "%s/#narrow/stream/" % (user_profile.realm.uri,)
+    base_url = f"{user_profile.realm.uri}/#narrow/stream/"
 
     streams_html = []
     streams_plain = []
 
     for stream in new_streams:
         narrow_url = base_url + encode_stream(stream.id, stream.name)
-        stream_link = "<a href='%s'>%s</a>" % (narrow_url, stream.name)
+        stream_link = f"<a href='{narrow_url}'>{stream.name}</a>"
         streams_html.append(stream_link)
         streams_plain.append(stream.name)
 

zerver/lib/email_mirror.py

@@ -69,7 +69,7 @@ def report_to_zulip(error_message: str) -> None:
         error_bot,
         error_stream,
         "email mirror error",
-        """~~~\n%s\n~~~""" % (error_message,)
+        f"""~~~\n{error_message}\n~~~"""
     )
 
 def log_and_report(email_message: EmailMessage, error_message: str, to: Optional[str]) -> None:
@@ -155,7 +155,7 @@ def construct_zulip_body(message: EmailMessage, realm: Realm, show_sender: bool=
 
     if show_sender:
         sender = handle_header_content(message.get("From", ""))
-        body = "From: %s\n%s" % (sender, body)
+        body = f"From: {sender}\n{body}"
 
     return body
 
@@ -279,7 +279,7 @@ def extract_and_upload_attachments(message: EmailMessage, realm: Realm) -> str:
                                              attachment,
                                              user_profile,
                                              target_realm=realm)
-                formatted_link = "[%s](%s)" % (filename, s3_url)
+                formatted_link = f"[{filename}]({s3_url})"
                 attachment_links.append(formatted_link)
             else:
                 logger.warning("Payload is not bytes (invalid attachment %s in message from %s).",

zerver/lib/email_mirror_helpers.py

@@ -60,7 +60,7 @@ def encode_email_address_helper(name: str, email_token: str, show_sender: bool=F
 
     # If encoded_name ends up empty, we just skip this part of the address:
     if encoded_name:
-        encoded_token = "%s.%s" % (encoded_name, email_token)
+        encoded_token = f"{encoded_name}.{email_token}"
     else:
         encoded_token = email_token
 

zerver/lib/email_notifications.py

@@ -93,16 +93,9 @@ def fix_emojis(content: str, base_url: str, emojiset: str) -> str:
         emoji_code = match.group('emoji_code')
         emoji_name = emoji_span_elem.get('title')
         alt_code = emoji_span_elem.text
-        image_url = base_url + '/static/generated/emoji/images-%(emojiset)s-64/%(emoji_code)s.png' % {
+        image_url = base_url + f'/static/generated/emoji/images-{emojiset}-64/{emoji_code}.png'
-            'emojiset': emojiset,
-            'emoji_code': emoji_code
-        }
         img_elem = lxml.html.fromstring(
-            '<img alt="%(alt_code)s" src="%(image_url)s" title="%(title)s">' % {
+            f'<img alt="{alt_code}" src="{image_url}" title="{emoji_name}">')
-                'alt_code': alt_code,
-                'image_url': image_url,
-                'title': emoji_name,
-            })
         img_elem.set('style', 'height: 20px;')
         img_elem.tail = emoji_span_elem.tail
         return img_elem
@@ -179,8 +172,8 @@ def build_message_list(user_profile: UserProfile, messages: List[Message]) -> Li
     def message_header(user_profile: UserProfile, message: Message) -> Dict[str, Any]:
         if message.recipient.type == Recipient.PERSONAL:
             narrow_link = get_narrow_url(user_profile, message)
-            header = "You and %s" % (message.sender.full_name,)
+            header = f"You and {message.sender.full_name}"
-            header_html = "<a style='color: #ffffff;' href='%s'>%s</a>" % (narrow_link, header)
+            header_html = f"<a style='color: #ffffff;' href='{narrow_link}'>{header}</a>"
         elif message.recipient.type == Recipient.HUDDLE:
             display_recipient = get_display_recipient(message.recipient)
             assert not isinstance(display_recipient, str)
@@ -188,15 +181,14 @@ def build_message_list(user_profile: UserProfile, messages: List[Message]) -> Li
                                          display_recipient=display_recipient)
             other_recipients = [r['full_name'] for r in display_recipient
                                 if r['id'] != user_profile.id]
-            header = "You and %s" % (", ".join(other_recipients),)
+            header = "You and {}".format(", ".join(other_recipients))
-            header_html = "<a style='color: #ffffff;' href='%s'>%s</a>" % (narrow_link, header)
+            header_html = f"<a style='color: #ffffff;' href='{narrow_link}'>{header}</a>"
         else:
             stream = Stream.objects.only('id', 'name').get(id=message.recipient.type_id)
             narrow_link = get_narrow_url(user_profile, message, stream=stream)
-            header = "%s > %s" % (stream.name, message.topic_name())
+            header = f"{stream.name} > {message.topic_name()}"
             stream_link = stream_narrow_url(user_profile.realm, stream)
-            header_html = "<a href='%s'>%s</a> > <a href='%s'>%s</a>" % (
+            header_html = f"<a href='{stream_link}'>{stream.name}</a> > <a href='{narrow_link}'>{message.topic_name()}</a>"
-                stream_link, stream.name, narrow_link, message.topic_name())
         return {"plain": header,
                 "html": header_html,
                 "stream_message": message.recipient.type_name() == "stream"}
@@ -371,11 +363,10 @@ def do_send_missedmessage_events_reply_in_zulip(user_profile: UserProfile,
             huddle_display_name = " and ".join(other_recipients)
             context.update({'huddle_display_name': huddle_display_name})
         elif len(other_recipients) == 3:
-            huddle_display_name = "%s, %s, and %s" % (
+            huddle_display_name = f"{other_recipients[0]}, {other_recipients[1]}, and {other_recipients[2]}"
-                other_recipients[0], other_recipients[1], other_recipients[2])
             context.update({'huddle_display_name': huddle_display_name})
         else:
-            huddle_display_name = "%s, and %s others" % (
+            huddle_display_name = "{}, and {} others".format(
                 ', '.join(other_recipients[:2]), len(other_recipients) - 2)
             context.update({'huddle_display_name': huddle_display_name})
     elif (missed_messages[0]['message'].recipient.type == Recipient.PERSONAL):
@@ -388,7 +379,7 @@ def do_send_missedmessage_events_reply_in_zulip(user_profile: UserProfile,
                             m['trigger'] == 'wildcard_mentioned'})
         message = missed_messages[0]['message']
         stream = Stream.objects.only('id', 'name').get(id=message.recipient.type_id)
-        stream_header = "%s > %s" % (stream.name, message.topic_name())
+        stream_header = f"{stream.name} > {message.topic_name()}"
         context.update({
             'stream_header': stream_header,
         })

zerver/lib/email_validation.py

@@ -112,7 +112,7 @@ def validate_email_is_valid(
     return None
 
 def email_reserved_for_system_bots_error(email: str) -> str:
-    return '%s is reserved for system bots' % (email,)
+    return f'{email} is reserved for system bots'
 
 def get_existing_user_errors(
     target_realm: Realm,

zerver/lib/error_notify.py

@@ -34,7 +34,7 @@ def user_info_str(report: Dict[str, Any]) -> str:
 def deployment_repr(report: Dict[str, Any]) -> str:
     deployment = 'Deployed code:\n'
     for field, val in report['deployment_data'].items():
-        deployment += '- %s: %s\n' % (field, val)
+        deployment += f'- {field}: {val}\n'
     return deployment
 
 def notify_browser_error(report: Dict[str, Any]) -> None:
@@ -44,7 +44,7 @@ def notify_browser_error(report: Dict[str, Any]) -> None:
     email_browser_error(report)
 
 def email_browser_error(report: Dict[str, Any]) -> None:
-    email_subject = "Browser error for %s" % (user_info_str(report),)
+    email_subject = f"Browser error for {user_info_str(report)}"
 
     body = ("User: %(user_full_name)s <%(user_email)s> on %(deployment)s\n\n"
             "Message:\n%(message)s\n\nStacktrace:\n%(stacktrace)s\n\n"
@@ -59,18 +59,18 @@ def email_browser_error(report: Dict[str, Any]) -> None:
     if more_info is not None:
         body += "\nAdditional information:"
         for (key, value) in more_info.items():
-            body += "\n  %s: %s" % (key, value)
+            body += f"\n  {key}: {value}"
 
-    body += "\n\nLog:\n%s" % (report['log'],)
+    body += "\n\nLog:\n{}".format(report['log'])
 
     mail_admins(email_subject, body)
 
 def zulip_browser_error(report: Dict[str, Any]) -> None:
-    email_subject = "JS error: %s" % (report['user_email'],)
+    email_subject = "JS error: {}".format(report['user_email'])
 
     user_info = user_info_str(report)
 
-    body = "User: %s\n" % (user_info,)
+    body = f"User: {user_info}\n"
     body += ("Message: %(message)s\n"
              % dict(report))
 
@@ -108,7 +108,7 @@ def zulip_server_error(report: Dict[str, Any]) -> None:
             val = report.get(field.lower())
             if field == "QUERY_STRING":
                 val = clean_data_from_query_parameters(str(val))
-            request_repr += "- %s: \"%s\"\n" % (field, val)
+            request_repr += f"- {field}: \"{val}\"\n"
         request_repr += "~~~~"
     else:
         request_repr = "Request info: none"
@@ -144,7 +144,7 @@ def email_server_error(report: Dict[str, Any]) -> None:
             val = report.get(field.lower())
             if field == "QUERY_STRING":
                 val = clean_data_from_query_parameters(str(val))
-            request_repr += "- %s: \"%s\"\n" % (field, val)
+            request_repr += f"- {field}: \"{val}\"\n"
     else:
         request_repr = "Request info: none\n"
 

zerver/lib/events.py

@@ -818,7 +818,7 @@ def apply_event(state: Dict[str, Any],
     elif event['type'] == 'has_zoom_token':
         state['has_zoom_token'] = event['value']
     else:
-        raise AssertionError("Unexpected event type %s" % (event['type'],))
+        raise AssertionError("Unexpected event type {}".format(event['type']))
 
 def do_events_register(user_profile: UserProfile, user_client: Client,
                        apply_markdown: bool = True,

zerver/lib/export.py

@@ -420,13 +420,13 @@ class Config:
                     using id_source.''')
             if self.id_source[0] != self.virtual_parent.table:
                 raise AssertionError('''
-                    Configuration error.  To populate %s, you
+                    Configuration error.  To populate {}, you
-                    want data from %s, but that differs from
+                    want data from {}, but that differs from
-                    the table name of your virtual parent (%s),
+                    the table name of your virtual parent ({}),
                     which suggests you many not have set up
                     the ordering correctly.  You may simply
                     need to assign a virtual_parent, or there
-                    may be deeper issues going on.''' % (
+                    may be deeper issues going on.'''.format(
                     self.table,
                     self.id_source[0],
                     self.virtual_parent.table))
@@ -466,7 +466,7 @@ def export_from_config(response: TableData, config: Config, seed_object: Optiona
         if config.custom_tables:
             for t in config.custom_tables:
                 if t not in response:
-                    raise AssertionError('Custom fetch failed to populate %s' % (t,))
+                    raise AssertionError(f'Custom fetch failed to populate {t}')
 
     elif config.concat_and_destroy:
         # When we concat_and_destroy, we are working with
@@ -1177,16 +1177,16 @@ def _check_key_metadata(email_gateway_bot: Optional[UserProfile],
     # Helper function for export_files_from_s3
     if 'realm_id' in key.metadata and key.metadata['realm_id'] != str(realm.id):
         if email_gateway_bot is None or key.metadata['user_profile_id'] != str(email_gateway_bot.id):
-            raise AssertionError("Key metadata problem: %s %s / %s" % (key.name, key.metadata, realm.id))
+            raise AssertionError(f"Key metadata problem: {key.name} {key.metadata} / {realm.id}")
         # Email gateway bot sends messages, potentially including attachments, cross-realm.
-        print("File uploaded by email gateway bot: %s / %s" % (key.key, key.metadata))
+        print(f"File uploaded by email gateway bot: {key.key} / {key.metadata}")
     elif processing_avatars:
         if 'user_profile_id' not in key.metadata:
-            raise AssertionError("Missing user_profile_id in key metadata: %s" % (key.metadata,))
+            raise AssertionError(f"Missing user_profile_id in key metadata: {key.metadata}")
         if int(key.metadata['user_profile_id']) not in user_ids:
-            raise AssertionError("Wrong user_profile_id in key metadata: %s" % (key.metadata,))
+            raise AssertionError(f"Wrong user_profile_id in key metadata: {key.metadata}")
     elif 'realm_id' not in key.metadata:
-        raise AssertionError("Missing realm_id in key metadata: %s" % (key.metadata,))
+        raise AssertionError(f"Missing realm_id in key metadata: {key.metadata}")
 
 def _get_exported_s3_record(
         bucket_name: str,
@@ -1233,11 +1233,11 @@ def _save_s3_object_to_file(key: ServiceResource, output_dir: str, processing_av
     else:
         fields = key.key.split('/')
         if len(fields) != 3:
-            raise AssertionError("Suspicious key with invalid format %s" % (key.key,))
+            raise AssertionError(f"Suspicious key with invalid format {key.key}")
         filename = os.path.join(output_dir, key.key)
 
     if "../" in filename:
-        raise AssertionError("Suspicious file with invalid format %s" % (filename,))
+        raise AssertionError(f"Suspicious file with invalid format {filename}")
 
     dirname = os.path.dirname(filename)
     if not os.path.exists(dirname):
@@ -1264,11 +1264,11 @@ def export_files_from_s3(realm: Realm, bucket_name: str, output_dir: Path,
             user_ids.add(user_profile.id)
 
     if processing_realm_icon_and_logo:
-        object_prefix = "%s/realm/" % (realm.id,)
+        object_prefix = f"{realm.id}/realm/"
     elif processing_emoji:
-        object_prefix = "%s/emoji/images/" % (realm.id,)
+        object_prefix = f"{realm.id}/emoji/images/"
     else:
-        object_prefix = "%s/" % (realm.id,)
+        object_prefix = f"{realm.id}/"
 
     if settings.EMAIL_GATEWAY_BOT is not None:
         email_gateway_bot: Optional[UserProfile] = get_system_bot(settings.EMAIL_GATEWAY_BOT)
@@ -1576,7 +1576,7 @@ def launch_user_message_subprocesses(threads: int, output_dir: Path,
     while pids:
         pid, status = os.wait()
         shard = pids.pop(pid)
-        print('Shard %s finished, status %s' % (shard, status))
+        print(f'Shard {shard} finished, status {status}')
 
 def do_export_user(user_profile: UserProfile, output_dir: Path) -> None:
     response: TableData = {}
@@ -1741,8 +1741,8 @@ def export_realm_wrapper(realm: Realm, output_dir: str,
     tarball_path = do_export_realm(realm=realm, output_dir=output_dir,
                                    threads=threads, public_only=public_only,
                                    consent_message_id=consent_message_id)
-    print("Finished exporting to %s" % (output_dir,))
+    print(f"Finished exporting to {output_dir}")
-    print("Tarball written to %s" % (tarball_path,))
+    print(f"Tarball written to {tarball_path}")
 
     if not upload:
         return None
@@ -1753,11 +1753,11 @@ def export_realm_wrapper(realm: Realm, output_dir: str,
     print("Uploading export tarball...")
     public_url = zerver.lib.upload.upload_backend.upload_export_tarball(realm, tarball_path)
     print()
-    print("Uploaded to %s" % (public_url,))
+    print(f"Uploaded to {public_url}")
 
     if delete_after_upload:
         os.remove(tarball_path)
-        print("Successfully deleted the tarball at %s" % (tarball_path,))
+        print(f"Successfully deleted the tarball at {tarball_path}")
     return public_url
 
 def get_realm_exports_serialized(user: UserProfile) -> List[Dict[str, Any]]:

zerver/lib/html_diff.py

@@ -4,7 +4,7 @@ from lxml.html.diff import htmldiff
 from typing import Optional
 
 def highlight_with_class(text: str, klass: str) -> str:
-    return '<span class="%s">%s</span>' % (klass, text)
+    return f'<span class="{klass}">{text}</span>'
 
 def highlight_html_differences(s1: str, s2: str, msg_id: Optional[int]=None) -> str:
     retval = htmldiff(s1, s2)

zerver/lib/import_realm.py

@@ -101,10 +101,10 @@ path_maps: Dict[str, Dict[str, str]] = {
 def update_id_map(table: TableName, old_id: int, new_id: int) -> None:
     if table not in ID_MAP:
         raise Exception('''
-            Table %s is not initialized in ID_MAP, which could
+            Table {} is not initialized in ID_MAP, which could
             mean that we have not thought through circular
             dependencies.
-            ''' % (table,))
+            '''.format(table))
     ID_MAP[table][old_id] = new_id
 
 def fix_datetime_fields(data: TableData, table: TableName) -> None:

zerver/lib/logging_util.py

@@ -70,7 +70,7 @@ class _RateLimitFilter:
         try:
             # Track duplicate errors
             duplicate = False
-            rate = getattr(settings, '%s_LIMIT' % (self.__class__.__name__.upper(),),
+            rate = getattr(settings, f'{self.__class__.__name__.upper()}_LIMIT',
                            600)  # seconds
 
             if rate > 0:

zerver/lib/management.py

@@ -28,7 +28,7 @@ def check_config() -> None:
         except AttributeError:
             pass
 
-        raise CommandError("Error: You must set %s in /etc/zulip/settings.py." % (setting_name,))
+        raise CommandError(f"Error: You must set {setting_name} in /etc/zulip/settings.py.")
 
 def sleep_forever() -> None:
     while True:  # nocoverage
@@ -127,7 +127,7 @@ You can use the command list_realms to find ID of the realms in this server."""
                 return UserProfile.objects.select_related().get(
                     delivery_email__iexact=email.strip(), realm=realm)
             except UserProfile.DoesNotExist:
-                raise CommandError("The realm '%s' does not contain a user with email '%s'" % (realm, email))
+                raise CommandError(f"The realm '{realm}' does not contain a user with email '{email}'")
 
         # Realm is None in the remaining code path.  Here, we
         # optimistically try to see if there is exactly one user with
@@ -139,7 +139,7 @@ You can use the command list_realms to find ID of the realms in this server."""
                                "(in different realms); please pass `--realm` "
                                "to specify which one to modify.")
         except UserProfile.DoesNotExist:
-            raise CommandError("This Zulip server does not contain a user with email '%s'" % (email,))
+            raise CommandError(f"This Zulip server does not contain a user with email '{email}'")
 
     def get_client(self) -> Client:
         """Returns a Zulip Client object to be used for things done in management commands"""

zerver/lib/message.py

@@ -519,7 +519,7 @@ class MessageDict:
                 elif recip['email'] > display_recipient[0]['email']:
                     display_recipient = [display_recipient[0], recip]
         else:
-            raise AssertionError("Invalid recipient type %s" % (recipient_type,))
+            raise AssertionError(f"Invalid recipient type {recipient_type}")
 
         obj['display_recipient'] = display_recipient
         obj['type'] = display_type
@@ -1019,7 +1019,7 @@ def apply_unread_message_event(user_profile: UserProfile,
         else:
             message_type = 'huddle'
     else:
-        raise AssertionError("Invalid message type %s" % (message['type'],))
+        raise AssertionError("Invalid message type {}".format(message['type']))
 
     sender_id = message['sender_id']
 

zerver/lib/migrate.py

@@ -28,11 +28,11 @@ def do_batch_update(cursor: CursorObj,
     if min_id is None:
         return
 
-    print("\n    Range of rows to update: [%s, %s]" % (min_id, max_id))
+    print(f"\n    Range of rows to update: [{min_id}, {max_id}]")
     while min_id <= max_id:
         lower = min_id
         upper = min_id + batch_size
-        print('    Updating range [%s,%s)' % (lower, upper))
+        print(f'    Updating range [{lower},{upper})')
         cursor.execute(stmt, [lower, upper])
 
         min_id = upper

zerver/lib/mobile_auth_otp.py

@@ -15,7 +15,7 @@ def xor_hex_strings(bytes_a: str, bytes_b: str) -> str:
     """Given two hex strings of equal length, return a hex string with
     the bitwise xor of the two hex strings."""
     assert len(bytes_a) == len(bytes_b)
-    return ''.join(["%x" % (int(x, 16) ^ int(y, 16),)
+    return ''.join([f"{int(x, 16) ^ int(y, 16):x}"
                     for x, y in zip(bytes_a, bytes_b)])
 
 def ascii_to_hex(input_string: str) -> str:

zerver/lib/outgoing_webhook.py

@@ -223,11 +223,11 @@ def notify_bot_owner(event: Dict[str, Any],
     bot_id = event['user_profile_id']
     bot_owner = get_user_profile_by_id(bot_id).bot_owner
 
-    notification_message = "[A message](%s) triggered an outgoing webhook." % (message_url,)
+    notification_message = f"[A message]({message_url}) triggered an outgoing webhook."
     if failure_message:
         notification_message += "\n" + failure_message
     if status_code:
-        notification_message += "\nThe webhook got a response with status code *%s*." % (status_code,)
+        notification_message += f"\nThe webhook got a response with status code *{status_code}*."
     if response_content:
         notification_message += "\nThe response contains the following payload:\n" \
                                 "```\n%s\n```" % (str(response_content),)
@@ -326,6 +326,6 @@ def do_rest_call(base_url: str,
         response_message = ("An exception of type *%s* occurred for message `%s`! "
                             "See the Zulip server logs for more information." % (
                                 type(e).__name__, event["command"],))
-        logging.exception("Outhook trigger failed:\n %s" % (e,))
+        logging.exception(f"Outhook trigger failed:\n {e}")
         fail_with_message(event, response_message)
         notify_bot_owner(event, exception=e)

zerver/lib/push_notifications.py

@@ -468,14 +468,14 @@ def get_gcm_alert(message: Message) -> str:
     """
     sender_str = message.sender.full_name
     if message.recipient.type == Recipient.HUDDLE and message.trigger == 'private_message':
-        return "New private group message from %s" % (sender_str,)
+        return f"New private group message from {sender_str}"
     elif message.recipient.type == Recipient.PERSONAL and message.trigger == 'private_message':
-        return "New private message from %s" % (sender_str,)
+        return f"New private message from {sender_str}"
     elif message.is_stream_message() and (message.trigger == 'mentioned' or
                                           message.trigger == 'wildcard_mentioned'):
-        return "New mention from %s" % (sender_str,)
+        return f"New mention from {sender_str}"
     else:  # message.is_stream_message() and message.trigger == 'stream_push_notify'
-        return "New stream message from %s in %s" % (sender_str, get_display_recipient(message.recipient),)
+        return f"New stream message from {sender_str} in {get_display_recipient(message.recipient)}"
 
 def get_mobile_push_content(rendered_content: str) -> str:
     def get_text(elem: lxml.html.HtmlElement) -> str:
@@ -586,7 +586,7 @@ def get_apns_alert_title(message: Message) -> str:
         assert isinstance(recipients, list)
         return ', '.join(sorted(r['full_name'] for r in recipients))
     elif message.is_stream_message():
-        return "#%s > %s" % (get_display_recipient(message.recipient), message.topic_name(),)
+        return f"#{get_display_recipient(message.recipient)} > {message.topic_name()}"
     # For personal PMs, we just show the sender name.
     return message.sender.full_name
 

zerver/lib/queue.py

@@ -38,7 +38,7 @@ class SimpleQueueClient:
         start = time.time()
         self.connection = pika.BlockingConnection(self._get_parameters())
         self.channel    = self.connection.channel()
-        self.log.info('SimpleQueueClient connected (connecting took %.3fs)' % (time.time() - start,))
+        self.log.info(f'SimpleQueueClient connected (connecting took {time.time() - start:.3f}s)')
 
     def _reconnect(self) -> None:
         self.connection = None
@@ -76,10 +76,10 @@ class SimpleQueueClient:
                                          credentials=credentials)
 
     def _generate_ctag(self, queue_name: str) -> str:
-        return "%s_%s" % (queue_name, str(random.getrandbits(16)))
+        return f"{queue_name}_{str(random.getrandbits(16))}"
 
     def _reconnect_consumer_callback(self, queue: str, consumer: Consumer) -> None:
-        self.log.info("Queue reconnecting saved consumer %s to queue %s" % (consumer, queue))
+        self.log.info(f"Queue reconnecting saved consumer {consumer} to queue {queue}")
         self.ensure_queue(queue, lambda: self.channel.basic_consume(queue,
                                                                     consumer,
                                                                     consumer_tag=self._generate_ctag(queue)))
@@ -115,7 +115,7 @@ class SimpleQueueClient:
                 properties=pika.BasicProperties(delivery_mode=2),
                 body=body)
 
-            statsd.incr("rabbitmq.publish.%s" % (queue_name,))
+            statsd.incr(f"rabbitmq.publish.{queue_name}")
 
         self.ensure_queue(queue_name, do_publish)
 

zerver/lib/rate_limiter.py

@@ -286,7 +286,7 @@ class TornadoInMemoryRateLimiterBackend(RateLimiterBackend):
             ratelimited, time_till_free = cls.need_to_limit(entity_key, time_window, max_count)
 
             if ratelimited:
-                statsd.incr("ratelimiter.limited.%s" % (entity_key,))
+                statsd.incr(f"ratelimiter.limited.{entity_key}")
                 break
 
         return ratelimited, time_till_free
@@ -450,7 +450,7 @@ class RedisRateLimiterBackend(RateLimiterBackend):
         ratelimited, time = cls.is_ratelimited(entity_key, rules)
 
         if ratelimited:
-            statsd.incr("ratelimiter.limited.%s" % (entity_key,))
+            statsd.incr(f"ratelimiter.limited.{entity_key}")
 
         else:
             try:

zerver/lib/realm_icon.py

@@ -12,6 +12,6 @@ def get_realm_icon_url(realm: Realm) -> str:
         return upload_backend.get_realm_icon_url(realm.id, realm.icon_version)
     elif settings.ENABLE_GRAVATAR:
         hash_key = gravatar_hash(realm.string_id)
-        return "https://secure.gravatar.com/avatar/%s?d=identicon" % (hash_key,)
+        return f"https://secure.gravatar.com/avatar/{hash_key}?d=identicon"
     else:
         return settings.DEFAULT_AVATAR_URI+'?version=0'

zerver/lib/redis_utils.py

@@ -63,4 +63,4 @@ def validate_key_fits_format(key: str, key_format: str) -> None:
     regex = key_format.format(token=r"[a-zA-Z0-9]+")
 
     if not re.fullmatch(regex, key):
-        raise ZulipRedisKeyOfWrongFormatError("%s does not match format %s" % (key, key_format))
+        raise ZulipRedisKeyOfWrongFormatError(f"{key} does not match format {key_format}")