当我尝试使用棉花糖将JSON格式的Python对象序列化并且AttributeError
触发了棉花糖枚举包时-'str' object has no attribute 'name'
我有以下与外键链接的类:
class BusinessUnitsManagement(db.Model, DatabaseObject):
__tablename__ = 'bu_mngmt'
id = db.Column(db.Integer(), primary_key=True)
bu_id = db.Column(db.Integer(), db.ForeignKey('business_units.id'), nullable=False)
head = db.Column(db.Integer(), db.ForeignKey('user_properties.id'), nullable=True)
bu_properties = db.relationship('BusinessUnits', foreign_keys=[bu_id], backref='bu_mngmt')
head_properties = db.relationship('UserProperty', foreign_keys=[head])
class UserProperty(db.Model, DatabaseObject):
__tablename__ = 'user_properties'
id = db.Column(db.Integer, db.ForeignKey('users.id'), primary_key=True)
seniority = db.Column(db.Enum(Seniority), nullable=True)
class BusinessUnits(db.Model):
__tablename__ = 'business_units'
id = db.Column(db.Integer(), primary_key=True)
name = db.Column(db.String(5), nullable=False)
description = db.Column(db.String(100), nullable=True)
另外,我为上述这些类创建Schema类:
from marshmallow import Schema, fields
from marshmallow_enum import EnumField
class BusinessUnitsManagementSchema(Schema):
id = fields.Int()
bu_properties = fields.Nested(BusinessUnitsSchema)
head_properties = fields.Nested(UserPropertySchema)
class UserPropertySchema(Schema):
id = fields.Int()
full_name = fields.Str()
seniority = EnumField(Seniority)
class BusinessUnitsSchema(Schema):
id = fields.Int()
name = fields.Str()
description = fields.Str()
资历定义为:
Seniority = Enum(
value='Seniority',
names=[
('Intern', 'Intern'),
('Junior_Engineer', 'Junior_Engineer'),
('Junior Engineer', 'Junior Engineer'),
('Design Engineer', 'Design Engineer'),
('Design_Engineer', 'Design_Engineer'),
('Senior Engineer', 'Senior Engineer'),
('Senior_Engineer', 'Senior_Engineer')
]
)
当我尝试获取Python对象的JSON格式时:
from marshmallow import Schema, fields
from marshmallow_enum import EnumField
objects = BusinessUnitsManagement.query.join(BusinessUnits).all()
result = []
for object in objects:
marshmallow_item = BusinessUnitsManagementSchema.dumps(object)
result.append(marshmallow_item.data)
return result
我在Ubuntu上收到此错误,但在Windows上一切正常:
marshmallow-enum version on both Win and Ubuntu --- 1.5.1
Python version on Win 10 ---------- 3.6.6
Python version on Ubuntu 16.04.3 -- 3.5.2
marshmallow_item = schema.dumps(item)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/schema.py", line 557, in dumps
deserialized, errors = self.dump(obj, many=many, update_fields=update_fields)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/schema.py", line 509, in dump
**kwargs
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 138, in serialize
index=(index if index_errors else None)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 62, in call_and_store
value = getter_func(data)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 132, in <lambda>
getter = lambda d: field_obj.serialize(attr_name, d, accessor=accessor)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/fields.py", line 252, in serialize
return self._serialize(value, attr, obj)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/fields.py", line 450, in _serialize
update_fields=not self.__updated_fields)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/schema.py", line 509, in dump
**kwargs
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 138, in serialize
index=(index if index_errors else None)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 62, in call_and_store
value = getter_func(data)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/marshalling.py", line 132, in <lambda>
getter = lambda d: field_obj.serialize(attr_name, d, accessor=accessor)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow/fields.py", line 252, in serialize
return self._serialize(value, attr, obj)
File ".../flaskvenv/lib/python3.5/site-packages/marshmallow_enum/__init__.py", line 80, in _serialize
return value.name
AttributeError: 'str' object has no attribute 'name'
问题与数据库有关,更具体地说,问题出在“高级”列的值上。有些行的“ seniority”设置为空白(不是NULL-只是空字符串),因此这就是序列化未正确完成的原因。我不知道这是怎么发生的,因为“高级”列设置为ENUM类型。
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我来说两句