给出以下代码,我想以一种可以将字符串传递到EnumField
构造函数中的方式修改MyClass
,并立即将它们自动广播为枚举。我本来想覆盖“设置者”,但在peewee的代码中找不到它。
from enum import Enum
from peewee import CharField, Model
class EnumField(CharField):
"Custom field to support enums"
def __init__(self, enum, **kwargs):
super(EnumField, self).__init__(**kwargs)
self.enum = enum
def db_value(self, value):
if isinstance(value, Enum):
return str(value.name) # convert enum to str
elif isinstance(value, basestring):
return value
return None
def python_value(self, value):
if value:
return self.enum[value] # convert str to enum
return None
def clone_base(self, **kwargs):
return super(EnumField, self).clone_base(enum=self.enum, **kwargs)
class FooEnum(Enum):
FOO = "foo"
BAR = "bar"
class MyClass(Model):
field1 = EnumField(FooEnum)
my_class = MyClass(field1='foo')
type(my_class.field1) == FooEnum # False, it's str but I would like it to be autocasted
my_class.save()
my_class = MyClass.get()
type(my_class.field1) == FooEnum # True
根据Peewee docs for fields,看来您缺少的方法是coerce
:
强制(值)
此方法是db_value和python_value默认使用的一种简写形式。通常,您可以仅执行此操作即可。
Parameters: value – arbitrary data from app or backend Return type: python data type
我将使coerce
与python_value
相同:
def python_value(self, value):
if value:
return self.enum[value] # convert str to enum
return None
coerce = python_value