AttributeError：“decimal.Decimal”对象没有“”decode“”属性“”

Question

我很难弄清楚为什么我会得到这个错误。我有一个名为Driver的模型，代码如下：

class Driver(models.Model):
userId = models.IntegerField(unique=True)
status = models.IntegerField(default=-1)
currentLatitude = models.DecimalField(max_digits=11, decimal_places=8, default=0)
currentLongitude = models.DecimalField(max_digits=11, decimal_places=8, default=0)

我正试图在我的tests.py文件中测试这个模型，并且在我的setUpTestData(cls)方法中创建了一个这样的驱动程序实例。

Driver.objects.create(userId=3, status=0, currentLatitude=37.717, currentLongitude=100)

我刚刚为lat/long设置了假的虚拟值，我想测试一下这个实例是否真的有37.717的currentLatitude和100的currentLongitude。

以下是我的一个测试：

    def testDriverLatitude(self):
        driver = Driver.objects.get(id=3)
        expected_latitude = driver.currentLatitude
        self.assertEquals(expected_latitude, 37.717)

当我运行测试时，在driver = Driver.objects.get(id=1)上得到一个错误

这是我得到的错误，AttributeError: 'decimal.Decimal' object has no attribute 'decode'

这是完整的跟踪堆栈

Traceback (most recent call last):
File "\server\backend\tests.py", line 51, in 
testDriverLatitude
driver = Driver.objects.get(id=3)
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\query.py", line 393, in get
num = len(clone)
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\query.py", line 250, in __len__
self._fetch_all()
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\query.py", line 1186, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\query.py", line 63, in __iter__
for row in compiler.results_iter(results):
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\sql\compiler.py", line 1466, in cursor_iter
for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\models\sql\compiler.py", line 1466, in <lambda>
for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\django\db\utils.py", line 96, in inner
return func(*args, **kwargs)
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\mysql\connector\cursor_cext.py", line 510, in fetchmany
rows.extend(self._cnx.get_rows(size)[0])
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\mysql\connector\connection_cext.py", line 280, in get_rows
row[i])
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\mysql\connector\conversion.py", line 205, in to_python
return self._cache_field_types[vtype[1]](value, vtype)
File "C:\Users\Andy\.virtualenvs\CS160-wrkGRq_z\lib\site- 
packages\mysql\connector\conversion.py", line 446, in _DECIMAL_to_python
val = value.decode(self.charset)
AttributeError: 'decimal.Decimal' object has no attribute 'decode'

我试着在网上寻找答案，但似乎找不到解决方案。

如有任何帮助或建议，我们将不胜感激。谢谢!

Answer 1

在使用最新版本的mysql-connector-python时，我也遇到了同样的问题。请尝试使用8.0.5版。