我正在使用django-rest-framework的简单通用视图，它在我的本地机器上工作正常，但在服务器中出现属性错误。这是错误：
AttributeError at /api/getcarts/ 'datetime.timedelta' object has no attribute 'decode'
这是班级：
class GetCarts(generics.ListAPIView):
serializer_class = CartSerializer
queryset = TblCarts.objects.all()
奇怪的是，所有其他GET和POST API都运行正常。这是TblCart：
class TblCarts(models.Model):
price = models.IntegerField()
location = models.CharField(max_length=500)
location_coordinate = models.CharField(max_length=100, default=0)
number = models.CharField(max_length=50)
promo_code = models.CharField(max_length=50, default=0)
receipt = models.CharField(max_length=100)
order_receive_date = models.DateField(auto_now_add=True)
order_receive_time = models.TimeField(auto_now_add=True)
order_dispatch_time = models.TimeField(default='00:00', max_length=100)
order_delivered_time = models.TimeField(default='00:00', max_length=100)
order_status = models.CharField(max_length=100, default=1)
class Meta:
managed = False
db_table = 'tbl_carts'
这是序列化器：
class CartSerializer(serializers.ModelSerializer):
class Meta:
model = TblCarts
fields = '__all__'
我无法弄清楚问题是什么。版本是：python 3.6.5，Django 2.1，djangorestframework 3.8.2。
错误追溯：
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
34. response = get_response(request)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
126. response = self.process_exception_by_middleware(e, request)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
124. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/views/decorators/csrf.py" in wrapped_view
54. return view_func(*args, **kwargs)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/views/generic/base.py" in view
68. return self.dispatch(request, *args, **kwargs)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/views.py" in dispatch
483. response = self.handle_exception(exc)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/views.py" in handle_exception
443. self.raise_uncaught_exception(exc)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/views.py" in dispatch
480. response = handler(request, *args, **kwargs)
File "/var/www/khaanpin/khanpinuser/api/views.py" in get
51. return Response({'error': 'false', 'data': CartSerializer(orders, many=True).data})
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/serializers.py" in data
765. ret = super(ListSerializer, self).data
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/serializers.py" in data
262. self._data = self.to_representation(self.instance)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/rest_framework/serializers.py" in to_representation
683. self.child.to_representation(item) for item in iterable
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/models/query.py" in __iter__
268. self._fetch_all()
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/models/query.py" in _fetch_all
1183. self._result_cache = list(self._iterable_class(self))
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/models/query.py" in __iter__
63. for row in compiler.results_iter(results):
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in cursor_iter
1462. for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in <lambda>
1462. for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/django/db/utils.py" in inner
96. return func(*args, **kwargs)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/mysql/connector/cursor_cext.py" in fetchmany
510. rows.extend(self._cnx.get_rows(size)[0])
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/mysql/connector/connection_cext.py" in get_rows
280. row[i])
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/mysql/connector/conversion.py" in to_python
205. return self._cache_field_types[vtype[1]](value, vtype)
File "/var/www/khaanpin/khanpinuser/venv3/lib/python3.6/site-packages/mysql/connector/django/base.py" in _TIME_to_python
106. return dateparse.parse_time(value.decode('utf-8'))
Exception Type: AttributeError at /api/getcarts/
Exception Value: 'datetime.timedelta' object has no attribute 'decode'
Request information:
USER: 9999999999
GET: No GET data
POST: No POST data
FILES: No FILES data
COOKIES: No cookie data
问题似乎与您正在使用的数据库连接器有关。
我解决这个问题的方法是在连接数据库时使用mysql-connector-c而不是mysql-client。
我使用 this lib (mysqlclient 1.4.2.post1) 解决了我的问题，但最后还有另一种选择。
步骤是：
pip install mysql-connector-pythonpip install mysqlclient'default': env.db('DB_DEFAULT', default=f'mysql-connector://root:password@{HOST_MYSQL}:3306/YOUR_DB')
到'default': env.db('DB_DEFAULT', default=f'mysql://root:password@{HOST_MYSQL}:3306/YOUR_DB')另一种选择是将use_pure从db选项更改为true，您可以通过将?use_pure=True查询字符串添加到连接URL来实现。
最后一个可能会影响连接性能，因为它确保它将使用Python的纯连接器而不是它的编译版本。
不要使用：
order_dispatch_time = models.TimeField(default='00:00', max_length=100)
order_delivered_time = models.TimeField(default='00:00', max_length=100)
改为使用：
import datetime
<...you model ...>
order_dispatch_time = models.TimeField(default=datetime.time(00,00))
order_delivered_time = models.TimeField(default=datetime.time(00,00))
如果您使用'mysql-connector-python'请尝试使用版本8.0.5。使用最新版本的'mysql-connector-python'时遇到了同样的问题。