Python django.db.models.TimeField() Examples

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.rel, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon
    from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return _boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return smart_text(value) 

def display_for_field(value, field, empty_value_display):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon

    if getattr(field, 'flatchoices', None):
        return dict(field.flatchoices).get(value, empty_value_display)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, (models.BooleanField, models.NullBooleanField)):
        return _boolean_icon(value)
    elif value is None:
        return empty_value_display
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return display_for_value(value, empty_value_display) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def load_dates(context):
    data = {}
    cl = context.get('cl')
    if cl.has_filters:
        for spec in cl.filter_specs:
            # 自定义的filter，没有field
            if not hasattr(spec, 'field'):
                continue

            field = spec.field
            field_type = None
            if isinstance(field, models.DateTimeField):
                field_type = 'datetime'
            elif isinstance(field, models.DateField):
                field_type = 'date'
            elif isinstance(field, models.TimeField):
                field_type = 'time'

            if field_type:
                data[spec.field_path] = field_type
    context['date_field'] = data

    return '<script type="text/javascript">var searchDates={}</script>'.format(json.dumps(data, cls=LazyEncoder)) 

def display_for_field(value, field, empty_value_display):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon

    if getattr(field, 'flatchoices', None):
        return dict(field.flatchoices).get(value, empty_value_display)
    # BooleanField needs special-case null-handling, so it comes before the
    # general null test.
    elif isinstance(field, models.BooleanField):
        return _boolean_icon(value)
    elif value is None:
        return empty_value_display
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return display_for_value(value, empty_value_display) 

def display_for_field(value, field, empty_value_display):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon

    if getattr(field, 'flatchoices', None):
        return dict(field.flatchoices).get(value, empty_value_display)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return _boolean_icon(value)
    elif value is None:
        return empty_value_display
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return display_for_value(value, empty_value_display) 

def display_for_field(value, field, empty_value_display):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon

    if field.flatchoices:
        return dict(field.flatchoices).get(value, empty_value_display)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return _boolean_icon(value)
    elif value is None:
        return empty_value_display
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field, empty_value_display):
    from django.contrib.admin.templatetags.admin_list import _boolean_icon

    if getattr(field, 'flatchoices', None):
        return dict(field.flatchoices).get(value, empty_value_display)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return _boolean_icon(value)
    elif value is None:
        return empty_value_display
    elif isinstance(field, models.DateTimeField):
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return display_for_value(value, empty_value_display) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.rel, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return smart_text(value) 

def test_nested_subquery_outer_ref_2(self):
        if django.VERSION < (1, 11, 0):
            self.skipTest("does not work on older django")
        first = Time.objects.create(time='09:00')
        second = Time.objects.create(time='17:00')
        third = Time.objects.create(time='21:00')
        SimulationRun.objects.bulk_create([
            SimulationRun(start=first, end=second, midpoint='12:00'),
            SimulationRun(start=first, end=third, midpoint='15:00'),
            SimulationRun(start=second, end=first, midpoint='00:00'),
        ])
        inner = Time.objects.filter(time=OuterRef(OuterRef('time')), pk=OuterRef('start')).values('time')
        middle = SimulationRun.objects.annotate(other=Subquery(inner)).values('other')[:1]
        outer = Time.objects.annotate(other=Subquery(middle, output_field=models.TimeField()))
        # This is a contrived example. It exercises the double OuterRef form.
        self.assertCountEqual(outer, [first, second, third]) 

def test_time_field(self):
        field = models.TimeField()
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(path, "django.db.models.TimeField")
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {})

        field = models.TimeField(auto_now=True)
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'auto_now': True})

        field = models.TimeField(auto_now_add=True)
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'auto_now_add': True}) 

def test_trunc_date_func(self):
        start_datetime = microsecond_support(datetime(2015, 6, 15, 14, 30, 50, 321))
        end_datetime = microsecond_support(datetime(2016, 6, 15, 14, 10, 50, 123))
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncDate('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, start_datetime.date()),
                (end_datetime, end_datetime.date()),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime__date=TruncDate('start_datetime')).count(), 2)

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateField"):
            list(DTModel.objects.annotate(truncated=TruncDate('start_time')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateField"):
            list(DTModel.objects.annotate(truncated=TruncDate('start_time', output_field=TimeField()))) 

def test_trunc_time_func(self):
        start_datetime = microsecond_support(datetime(2015, 6, 15, 14, 30, 50, 321))
        end_datetime = microsecond_support(datetime(2016, 6, 15, 14, 10, 50, 123))
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncTime('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, start_datetime.time()),
                (end_datetime, end_datetime.time()),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime__time=TruncTime('start_datetime')).count(), 2)

        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
            list(DTModel.objects.annotate(truncated=TruncTime('start_date')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
            list(DTModel.objects.annotate(truncated=TruncTime('start_date', output_field=DateField()))) 

def test_trunc_day_func(self):
        start_datetime = microsecond_support(datetime(2015, 6, 15, 14, 30, 50, 321))
        end_datetime = truncate_to(microsecond_support(datetime(2016, 6, 15, 14, 10, 50, 123)), 'day')
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncDay('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, truncate_to(start_datetime, 'day')),
                (end_datetime, truncate_to(end_datetime, 'day')),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime=TruncDay('start_datetime')).count(), 1)

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncDay('start_time')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncDay('start_time', output_field=TimeField()))) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def display_for_field(value, field):
    from xadmin.views.list import EMPTY_CHANGELIST_VALUE

    if field.flatchoices:
        return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
    # NullBooleanField needs special-case null-handling, so it comes
    # before the general null test.
    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
        return boolean_icon(value)
    elif value is None:
        return EMPTY_CHANGELIST_VALUE
    elif isinstance(field, models.DateTimeField):
        return formats.localize(tz_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, models.FloatField):
        return formats.number_format(value)
    elif isinstance(field.remote_field, models.ManyToManyRel):
        return ', '.join([smart_text(obj) for obj in value.all()])
    else:
        return smart_text(value) 

def test_time_field(self):
        field = models.TimeField()
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(path, "django.db.models.TimeField")
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {})

        field = models.TimeField(auto_now=True)
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'auto_now': True})

        field = models.TimeField(auto_now_add=True)
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'auto_now_add': True}) 

def test_trunc_week_func(self):
        start_datetime = datetime(2015, 6, 15, 14, 30, 50, 321)
        end_datetime = truncate_to(datetime(2016, 6, 15, 14, 10, 50, 123), 'week')
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncWeek('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, truncate_to(start_datetime, 'week')),
                (end_datetime, truncate_to(end_datetime, 'week')),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime=TruncWeek('start_datetime')).count(), 1)

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncWeek('start_time')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncWeek('start_time', output_field=TimeField()))) 

def test_trunc_date_func(self):
        start_datetime = datetime(2015, 6, 15, 14, 30, 50, 321)
        end_datetime = datetime(2016, 6, 15, 14, 10, 50, 123)
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncDate('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, start_datetime.date()),
                (end_datetime, end_datetime.date()),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime__date=TruncDate('start_datetime')).count(), 2)

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateField"):
            list(DTModel.objects.annotate(truncated=TruncDate('start_time')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateField"):
            list(DTModel.objects.annotate(truncated=TruncDate('start_time', output_field=TimeField()))) 

def test_trunc_time_func(self):
        start_datetime = datetime(2015, 6, 15, 14, 30, 50, 321)
        end_datetime = datetime(2016, 6, 15, 14, 10, 50, 123)
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncTime('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, start_datetime.time()),
                (end_datetime, end_datetime.time()),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime__time=TruncTime('start_datetime')).count(), 2)

        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
            list(DTModel.objects.annotate(truncated=TruncTime('start_date')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
            list(DTModel.objects.annotate(truncated=TruncTime('start_date', output_field=DateField()))) 

def test_trunc_day_func(self):
        start_datetime = datetime(2015, 6, 15, 14, 30, 50, 321)
        end_datetime = truncate_to(datetime(2016, 6, 15, 14, 10, 50, 123), 'day')
        if settings.USE_TZ:
            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
        self.create_model(start_datetime, end_datetime)
        self.create_model(end_datetime, start_datetime)
        self.assertQuerysetEqual(
            DTModel.objects.annotate(extracted=TruncDay('start_datetime')).order_by('start_datetime'),
            [
                (start_datetime, truncate_to(start_datetime, 'day')),
                (end_datetime, truncate_to(end_datetime, 'day')),
            ],
            lambda m: (m.start_datetime, m.extracted)
        )
        self.assertEqual(DTModel.objects.filter(start_datetime=TruncDay('start_datetime')).count(), 1)

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncDay('start_time')))

        with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateTimeField"):
            list(DTModel.objects.annotate(truncated=TruncDay('start_time', output_field=TimeField()))) 

def test_time_subtraction(self):
        Time.objects.create(time=datetime.time(12, 30, 15, 2345))
        queryset = Time.objects.annotate(
            difference=ExpressionWrapper(
                F('time') - Value(datetime.time(11, 15, 0), output_field=models.TimeField()),
                output_field=models.DurationField(),
            )
        )
        self.assertEqual(
            queryset.get().difference,
            datetime.timedelta(hours=1, minutes=15, seconds=15, microseconds=2345)
        )

        queryset = Time.objects.annotate(difference=ExpressionWrapper(
            F('time') - Value(None, output_field=models.TimeField()),
            output_field=models.DurationField(),
        ))
        self.assertIsNone(queryset.first().difference)

        queryset = Time.objects.annotate(shifted=ExpressionWrapper(
            F('time') - Value(None, output_field=models.DurationField()),
            output_field=models.TimeField(),
        ))
        self.assertIsNone(queryset.first().shifted) 

def display_for_field(value, field, html=True, only_date=True):
    if getattr(field, 'flatchoices', None):
        if html and field.name == 'color' and value:
            return make_color_icon(value)
        return dict(field.flatchoices).get(value, '')
    elif html and (isinstance(field, (models.BooleanField, models.NullBooleanField))):
        return make_boolean_icon(value)
    elif isinstance(field, (models.BooleanField, models.NullBooleanField)):
        boolchoice = {False: "否", True: "是"}
        return boolchoice.get(value)
    elif value is None:
        return ""
    elif isinstance(field, models.DecimalField):
        return formats.number_format(value, field.decimal_places)
    elif isinstance(field, (models.IntegerField, models.FloatField)):
        return formats.number_format(value)
    elif isinstance(field, models.ForeignKey) and value:
        rel_obj = field.related_model.objects.get(pk=value)
        if html and COLOR_FK_FIELD and isinstance(rel_obj, Option):
            text_color = rel_obj.color
            if not text_color:
                text_color = 'text-info'
            safe_value = format_html(
                '<span class="text-{}">{}</span>', text_color, rel_obj.text)
            return safe_value
        return force_text(rel_obj)
    elif isinstance(field, models.TextField) and value:
        return force_text(value)
    elif isinstance(field, models.DateTimeField):
        if only_date:
            return formats.date_format(value)
        return formats.localize(timezone.template_localtime(value))
    elif isinstance(field, (models.DateField, models.TimeField)):
        return formats.localize(value)
    elif isinstance(field, models.FileField) and value:
        return format_html('<a href="{}">{}</a>', value.url, value)
    else:
        return display_for_value(value) 

def handle_field(self, obj, field):
        # A nasty special case: base YAML doesn't support serialization of time
        # types (as opposed to dates or datetimes, which it does support). Since
        # we want to use the "safe" serializer for better interoperability, we
        # need to do something with those pesky times. Converting 'em to strings
        # isn't perfect, but it's better than a "!!python/time" type which would
        # halt deserialization under any other language.
        if isinstance(field, models.TimeField) and getattr(obj, field.name) is not None:
            self._current[field.name] = str(getattr(obj, field.name))
        else:
            super(Serializer, self).handle_field(obj, field)