Make usage of django-timezone more explicit in code

The `timezone` module name is very ambiguous within Django, so whereever
we use django-timezone's `timezone` module make it clearer by naming it
`djtz`.

icekit_events/admin.py

@@ -30,7 +30,7 @@
 from icekit.admin import (
     ChildModelFilter, ChildModelPluginPolymorphicParentModelAdmin)
 from polymorphic.admin import PolymorphicChildModelAdmin
-from timezone import timezone
+from timezone import timezone as djtz  # django-timezone
 
 from icekit.publishing import admin as publishing_admin
 
@@ -176,12 +176,12 @@ def calendar_data(self, request):
         to be loaded in an iframe.
         """
         if 'timezone' in request.GET:
-            tz = timezone.get(request.GET.get('timezone'))
+            tz = djtz.get(request.GET.get('timezone'))
         else:
             tz = get_current_timezone()
-        start = timezone.localize(
+        start = djtz.localize(
             datetime.datetime.strptime(request.GET['start'], '%Y-%m-%d'), tz)
-        end = timezone.localize(
+        end = djtz.localize(
             datetime.datetime.strptime(request.GET['end'], '%Y-%m-%d'), tz)
 
         all_occurrences = models.Occurrence.objects.draft().overlapping(start, end)
@@ -210,8 +210,8 @@ def _calendar_json_for_occurrence(self, occurrence):
             # included in the calendar.
             end = occurrence.start + timedelta(days=1)
         else:
-            start = timezone.localize(occurrence.start)
-            end = timezone.localize(occurrence.end)
+            start = djtz.localize(occurrence.start)
+            end = djtz.localize(occurrence.end)
         if occurrence.is_cancelled and occurrence.cancel_reason:
             title = u"{0} [{1}]".format(
                 occurrence.event.title, occurrence.cancel_reason)
@@ -288,7 +288,7 @@ def preview(self, request):
         limit = int(request.POST.get('limit', 10))
         try:
             rruleset = rrule.rrulestr(
-                recurrence_rule, dtstart=timezone.now(), forceset=True)
+                recurrence_rule, dtstart=djtz.now(), forceset=True)
         except ValueError as e:
             data = {
                 'error': six.text_type(e),

icekit_events/models.py

@@ -9,7 +9,7 @@
 from dateutil import rrule
 import six
 import pytz
-from timezone import timezone
+from timezone import timezone as djtz  # django-timezone
 
 from django.core.urlresolvers import reverse
 from django.conf import settings
@@ -22,7 +22,6 @@
     get_current_timezone
 
 from polymorphic.models import PolymorphicModel
-from timezone.timezone import localize, now
 
 from icekit.content_collections.abstract_models import AbstractListingPage, \
     TitleSlugMixin
@@ -31,7 +30,7 @@
 from icekit.publishing.middleware import is_draft_request_context
 from django.template.defaultfilters import date as datefilter
 
-from . import appsettings, validators, utils
+from . import appsettings, validators
 from .utils import timeutils
 
 
@@ -57,7 +56,7 @@ def zero_datetime(dt, tz=None):
 
 def default_starts():
     when = timeutils.round_datetime(
-        when=timezone.now(),
+        when=djtz.now(),
         precision=appsettings.DEFAULT_STARTS_PRECISION,
         rounding=timeutils.ROUND_UP,
     )
@@ -69,7 +68,7 @@ def default_ends():
 
 
 def default_date_starts():
-    return timezone.date()
+    return djtz.date()
 
 
 def default_date_ends():
@@ -161,9 +160,9 @@ class AbstractBaseModel(models.Model):
     """
 
     created = models.DateTimeField(
-        default=timezone.now, db_index=True, editable=False)
+        default=djtz.now, db_index=True, editable=False)
     modified = models.DateTimeField(
-        default=timezone.now, db_index=True, editable=False)
+        default=djtz.now, db_index=True, editable=False)
 
     class Meta:
         abstract = True
@@ -174,7 +173,7 @@ def save(self, *args, **kwargs):
         """
         Update ``self.modified``.
         """
-        self.modified = timezone.now()
+        self.modified = djtz.now()
         super(AbstractBaseModel, self).save(*args, **kwargs)
 
 
@@ -526,7 +525,7 @@ def generate(self, until=None):
             if self.repeat_end:
                 until = self.repeat_end
             else:
-                until = timezone.now() + appsettings.REPEAT_LIMIT
+                until = djtz.now() + appsettings.REPEAT_LIMIT
         # Make datetimes naive, since RRULE spec contains naive datetimes so
         # our constraints must be the same
         start_dt = coerce_naive(start_dt)
@@ -560,7 +559,7 @@ def _build_complete_rrule(self, start_dt=None, until=None):
             start_dt = self.start
         if until is None:
             until = self.repeat_end \
-                or timezone.now() + appsettings.REPEAT_LIMIT
+                or djtz.now() + appsettings.REPEAT_LIMIT
         # We assume `recurrence_rule` is always a RRULE repeat spec of the form
         # "FREQ=DAILY", "FREQ=WEEKLY", etc?
         rrule_spec = "DTSTART:%s" % format_naive_ical_dt(start_dt)
@@ -755,11 +754,11 @@ def __str__(self):
 
     @property
     def local_start(self):
-        return localize(self.start)
+        return djtz.localize(self.start)
 
     @property
     def local_end(self):
-        return localize(self.end)
+        return djtz.localize(self.end)
 
     @property
     def is_generated(self):
@@ -802,7 +801,7 @@ def is_past(self):
         """
         :return: True if this occurrence is entirely in the past
         """
-        return self.end < now()
+        return self.end < djtz.now()
 
     def get_absolute_url(self):
         return self.event.get_absolute_url()
@@ -849,9 +848,9 @@ class Meta:
 
     def get_start(self, request):
         try:
-            start = timezone.parse('%s 00:00' % request.GET.get('date'))
+            start = djtz.parse('%s 00:00' % request.GET.get('date'))
         except ValueError:
-            start = timezone.midnight()
+            start = djtz.midnight()
         return start
 
     def get_days(self, request):

icekit_events/tests/tests.py

@@ -5,7 +5,7 @@
 
 # WebTest API docs: http://webtest.readthedocs.org/en/latest/api.html
 
-from timezone import timezone
+from timezone import timezone as djtz  # django-timezone
 from datetime import datetime, timedelta, time
 import six
 import json
@@ -19,14 +19,13 @@
 from django.forms.models import fields_for_model
 from django.test import TestCase
 from django.test.utils import override_settings
-from django.utils.timezone import make_naive
 
 from django_dynamic_fixture import G
 from django_webtest import WebTest
 
 from icekit_events import appsettings, forms, models
 from icekit_events.event_types.simple.models import SimpleEvent
-from icekit_events.models import get_occurrence_times_for_event
+from icekit_events.models import get_occurrence_times_for_event, coerce_naive
 from icekit_events.utils import timeutils
 
 
@@ -41,7 +40,7 @@ def setUp(self):
         )
         self.superuser.set_password('abc123')
         self.start = timeutils.round_datetime(
-            when=timezone.now(),
+            when=djtz.now(),
             precision=timedelta(minutes=1),
             rounding=timeutils.ROUND_DOWN)
         self.end = self.start + timedelta(minutes=45)
@@ -275,9 +274,9 @@ def test_event_with_repeatsgenerators_and_user_modified_occurrences(self):
         #######################################################################
         form = response.forms[0]
         extra_occurrence_start = (first_occurrence.start - timedelta(days=3)) \
-            .astimezone(timezone.get_current_timezone())
+            .astimezone(djtz.get_current_timezone())
         extra_occurrence_end = (first_occurrence.end - timedelta(days=3)) \
-            .astimezone(timezone.get_current_timezone())
+            .astimezone(djtz.get_current_timezone())
         form['occurrences-10-start_0'].value = \
             extra_occurrence_start.strftime('%Y-%m-%d')
         form['occurrences-10-start_1'].value = \
@@ -303,7 +302,7 @@ def test_event_with_repeatsgenerators_and_user_modified_occurrences(self):
         self.assertFalse(shifted_occurrence.is_user_modified)
         shifted_occurrence_start = \
             (shifted_occurrence.start + timedelta(minutes=30)) \
-            .astimezone(timezone.get_current_timezone())
+            .astimezone(djtz.get_current_timezone())
         form['occurrences-6-start_0'].value = \
             shifted_occurrence_start.strftime('%Y-%m-%d')
         form['occurrences-6-start_1'].value =\
@@ -449,7 +448,7 @@ def test_event_publishing(self):
             repeat_end.strftime('%H:%M:%S')
         # Add ad-hoc occurrence
         extra_occurrence_start = (self.start - timedelta(days=30)) \
-            .astimezone(timezone.get_current_timezone())
+            .astimezone(djtz.get_current_timezone())
         extra_occurrence_end = extra_occurrence_start + timedelta(hours=3)
         form['occurrences-0-start_0'].value = \
             extra_occurrence_start.strftime('%Y-%m-%d')
@@ -601,7 +600,7 @@ def test_admin_calendar(self):
         data = json.loads(response.content)
         self.assertEqual(2, len(data))
         def format_dt_like_fullcalendar(dt):
-            formatted = dt.astimezone(timezone.get_current_timezone()) \
+            formatted = dt.astimezone(djtz.get_current_timezone()) \
                 .strftime('%Y-%m-%dT%H:%M:%S%z')
             # FullCalendar includes ':' between hour & minute portions of the
             # timzone offset. There's no way to do this directly with Python's
@@ -676,7 +675,7 @@ class TestEventModel(TestCase):
 
     def setUp(self):
         self.start = timeutils.round_datetime(
-            when=timezone.now(),
+            when=djtz.now(),
             precision=timedelta(minutes=1),
             rounding=timeutils.ROUND_DOWN)
         self.end = self.start
@@ -726,9 +725,9 @@ def test_event_without_occurrences(self):
 
 class TestEventRepeatsGeneratorStrangeness(TestCase):
     def setUp(self):
-        self.start = timezone.datetime(2016,10,1, 9,0)
-        self.end = timezone.datetime(2016,10,1, 17)
-        self.repeat_end = timezone.datetime(2016,10,31, 17)
+        self.start = djtz.datetime(2016,10,1, 9,0)
+        self.end = djtz.datetime(2016,10,1, 17)
+        self.repeat_end = djtz.datetime(2016,10,31, 17)
 
         self.event = G(SimpleEvent)
 
@@ -744,29 +743,27 @@ def test_daily_occurrences(self):
         occurrences = self.event.occurrences.all()
         self.assertEquals(occurrences.count(), 31)
 
-        st = timezone.localize(self.start).time()
-        et = timezone.localize(self.end).time()
+        st = djtz.localize(self.start).time()
+        et = djtz.localize(self.end).time()
         self.assertEquals(st, time(9,0))
         self.assertEquals(et, time(17,0))
 
         for o in occurrences:
-            self.assertEquals(timezone.localize(o.start).time(), st)
-            self.assertEquals(timezone.localize(o.end).time(), et)
+            self.assertEquals(djtz.localize(o.start).time(), st)
+            self.assertEquals(djtz.localize(o.end).time(), et)
 
 class TestEventRepeatsGeneratorModel(TestCase):
 
     def setUp(self):
         """ Create a daily recurring event with no end date """
         self.start = timeutils.round_datetime(
-            when=timezone.now(),
+            when=djtz.now(),
             precision=timedelta(days=1),
             rounding=timeutils.ROUND_DOWN)
         self.end = self.start + appsettings.DEFAULT_ENDS_DELTA
 
-        self.naive_start = make_naive(
-            self.start, timezone.get_current_timezone())
-        self.naive_end = make_naive(
-            self.end, timezone.get_current_timezone())
+        self.naive_start = coerce_naive(self.start)
+        self.naive_end = coerce_naive(self.end)
 
     def test_uses_recurrencerulefield(self):
         """
@@ -956,7 +953,7 @@ def setUp(self):
         Create an event with a daily repeat generator.
         """
         self.start = timeutils.round_datetime(
-            when=timezone.now(),
+            when=djtz.now(),
             precision=timedelta(days=1),
             rounding=timeutils.ROUND_DOWN)
         self.end = self.start + appsettings.DEFAULT_ENDS_DELTA
@@ -980,13 +977,11 @@ def test_initial_event_occurrences_automatically_created(self):
         for days_hence in range(20):
             start = first_occurrence.start + timedelta(days=days_hence)
             self.assertTrue(
-                make_naive(start, timezone.get_current_timezone())
-                in occurrence_starts,
+                coerce_naive(start) in occurrence_starts,
                 "Missing start time %d days hence" % days_hence)
             end = first_occurrence.end + timedelta(days=days_hence)
             self.assertTrue(
-                make_naive(end, timezone.get_current_timezone())
-                in occurrence_ends,
+                coerce_naive(end) in occurrence_ends,
                 "Missing end time %d days hence" % days_hence)
         # Confirm Event correctly returns first & last occurrences
         self.assertEqual(
@@ -1075,12 +1070,10 @@ def test_add_arbitrary_occurrence_to_nonrepeating_event(self):
         self.assertTrue(added_occurrence.is_user_modified)
 
     def test_add_arbitrary_occurrences_to_repeating_event(self):
-        arbitrary_dt1 = make_naive(
-            self.start + timedelta(days=3, hours=-2),
-            timezone.get_current_timezone())
-        arbitrary_dt2 = make_naive(
-            self.start + timedelta(days=7, hours=5),
-            timezone.get_current_timezone())
+        arbitrary_dt1 = coerce_naive(
+            self.start + timedelta(days=3, hours=-2))
+        arbitrary_dt2 = coerce_naive(
+            self.start + timedelta(days=7, hours=5))
         event = G(SimpleEvent)
         generator = G(
             models.EventRepeatsGenerator,
@@ -1143,10 +1136,10 @@ def test_cancel_arbitrary_occurrence_from_repeating_event(self):
         occurrence_to_cancel_2 = event.occurrences.all()[5]
         occurrence_starts, __ = get_occurrence_times_for_event(event)
         self.assertTrue(
-            make_naive(occurrence_to_cancel_1.start, timezone.get_current_timezone())
+            coerce_naive(occurrence_to_cancel_1.start)
             in occurrence_starts)
         self.assertTrue(
-            make_naive(occurrence_to_cancel_2.start, timezone.get_current_timezone())
+            coerce_naive(occurrence_to_cancel_2.start)
             in occurrence_starts)
         # Cancel occurrences
         event.cancel_occurrence(occurrence_to_cancel_1)

icekit_events/utils/timeutils.py

@@ -1,6 +1,6 @@
 from datetime import datetime, timedelta
 
-from timezone import timezone
+from timezone import timezone as djtz  # django-timezone
 
 ROUND_DOWN = 'ROUND_DOWN'
 ROUND_NEAREST = 'ROUND_NEAREST'
@@ -40,7 +40,7 @@ def round_datetime(when=None, precision=60, rounding=ROUND_NEAREST):
             The rounding method to use (ROUND_DOWN, ROUND_NEAREST, ROUND_UP).
 
     """
-    when = when or timezone.now()
+    when = when or djtz.now()
     weekday = WEEKDAYS.get(precision, WEEKDAYS['MON'])
     if precision in WEEKDAYS:
         precision = int(timedelta(days=7).total_seconds())
@@ -49,7 +49,7 @@ def round_datetime(when=None, precision=60, rounding=ROUND_NEAREST):
     # Get delta between the beginning of time and the given datetime object.
     # If precision is a weekday, the beginning of time must be that same day.
     when_min = when.min + timedelta(days=weekday)
-    if timezone.is_aware(when):
+    if djtz.is_aware(when):
         # It doesn't seem to be possible to localise `datetime.min` without
         # raising `OverflowError`, so create a timezone aware object manually.
         when_min = datetime(tzinfo=when.tzinfo, *when_min.timetuple()[:3])