Django List Comprehension - Trouble Comparing Datetime Objects. TypeError: unorderable types: datetime.date() <= str()

Question

在我的模型中，我有以下方法：

def _bags_remaining(self):
    current_set = SortingRecords.objects.values().filter(~Q(id=self.id), tag=self.tag)
    sorted = [SortingRecords['bags_sorted'] for SortingRecords in current_set if
              SortingRecords['date'] <= self.date]
    remaining = self.tag.pieces - sum(sorted) - self.bags_sorted
    return remaining
bags_remaining = property(_bags_remaining)

它旨在查找到目前为止在与记录关联的标签下分类的行李数量，并从行李总数中扣除该数量（连同在该记录下分类的数量）。

效果很好！适当的金额已成功传递到模板。

然而，令我失望的是它取消了我的单元测试。

======================================================================
ERROR: test_sorting_records_bags_remaining_calculation (AlmondKing.InventoryLogs.tests.test_views.test_purchase_details.DetailsPageTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Projects\AlmondKing\AlmondKing\InventoryLogs\tests\test_views\test_purchase_details.py", line 155, in test_sorting_records_bags_remaining_calculation
    self.assertEqual(self.sortrecord1.bags_remaining, 79)
  File "C:\Projects\AlmondKing\AlmondKing\InventoryLogs\models.py", line 115, in _bags_remaining
    sorted = [SortingRecords['bags_sorted'] for SortingRecords in current_set if
  File "C:\Projects\AlmondKing\AlmondKing\InventoryLogs\models.py", line 116, in <listcomp>
    SortingRecords['date'] <= self.date]
TypeError: unorderable types: datetime.date() <= str()

----------------------------------------------------------------------
Ran 22 tests in 0.203s

FAILED (errors=2)
Destroying test database for alias 'default'...

它似乎将我的日期对象解释为字符串。它从中提取的模型是 DateField。如果我在上面调用类型，它会报告为：

这是它所在的型号：

class SortingRecords(models.Model):
    tag = models.ForeignKey(Purchase, related_name='sorting_record')
    date = models.DateField()
    bags_sorted = models.IntegerField()
    turnout = models.IntegerField()
    objects = models.Manager()

    def __str__(self):
        return "%s  [%s]" % (self.date, self.tag.tag)

这是我的考试运行。

# Sorting Records should calculate bags remaining for each entry.
def test_sorting_records_bags_remaining_calculation(self):
    self.assertEqual(self.sortrecord1.bags_remaining, 79)
    self.assertEqual(self.sortrecord2.bags_remaining, 39)
    self.assertEqual(self.sortrecord3.bags_remaining, 9)

同样，它在现实生活中有效，但在运行测试中失败了。有什么想法吗？

编辑以添加详细信息：

使用的数据库是 Postgres。

这是我的测试 setUpTestData():

class DetailsPageTest(TestCase):


@classmethod
def setUpTestData(cls):

    cls.product1 = ProductGroup.objects.create(
                        product_name="Almonds"
                        )
    cls.variety1 = Variety.objects.create(
                        product_group = cls.product1,
                        variety_name = "non pareil",
                        husked = False,
                        finished = False,
                        )

    cls.supplier1 = Supplier.objects.create(
                        company_name = "Acme",
                        company_location = "Acme Acres",
                        contact_info = "Call me!"
                        )

    cls.shipment1 = Purchase.objects.create(
                        tag=9,
                        shipment_id=9999,
                        supplier_id = cls.supplier1,
                        purchase_date='2015-01-09',
                        purchase_price=9.99,
                        product_name=cls.variety1,
                        pieces=99,
                        kgs=999,
                        crackout_estimate=99.9
                        )
    cls.shipment2 = Purchase.objects.create(
                        tag=8,
                        shipment_id=8888,
                        supplier_id=cls.supplier1,
                        purchase_date='2015-01-08',
                        purchase_price=8.88,
                        product_name=cls.variety1,
                        pieces=88,
                        kgs=888,
                        crackout_estimate=88.8
                        )
    cls.shipment3 = Purchase.objects.create(
                        tag=7,
                        shipment_id=7777,
                        supplier_id=cls.supplier1,
                        purchase_date='2014-01-07',
                        purchase_price=7.77,
                        product_name=cls.variety1,
                        pieces=77,
                        kgs=777,
                        crackout_estimate=77.7
                        )

    cls.sortrecord1 = SortingRecords.objects.create(
                        tag=cls.shipment1,
                        date="2015-02-05",
                        bags_sorted=20,
                        turnout=199,
                        )

    cls.sortrecord2 = SortingRecords.objects.create(
                        tag=cls.shipment1,
                        date="2015-02-07",
                        bags_sorted=40,
                        turnout=399,
                        )
    cls.sortrecord3 = SortingRecords.objects.create(
                        tag=cls.shipment1,
                        date='2015-02-09',
                        bags_sorted=30,
                        turnout=299,
                        )

Answer 1

感谢 @bruno desthuilliers 我发现了这个问题。

我的 setUpTestData() 方法是用字符串而不是日期时间对象填充字段。将它们转换为适当的输入后它可以正常工作：

purchase_date=datetime.date(2015,1,9)

Django List Comprehension - Trouble Comparing Datetime Objects. TypeError: unorderable types: datetime.date() <= str()

Django List Comprehension - Trouble Comparing Datetime Objects. TypeError: unorderable types: datetime.date() <= str()

python

django

datetime

django-models

django-testing