如果在字段中传入None,我可以在Pydantic中设置默认值吗?
我有以下代码,但我认为此处的验证器仅适用于模型的初始化,而不是其他情况。
我的代码:
class User(BaseModel):
name: Optional[str] = ''
password: Optional[str] = ''
email: EmailStr
@validator('name')
def set_name(cls, name):
return name or 'foo'
遇到的问题:
user = User(name=None, password='some_password', email='user@example.com')
print("Name is ", user.name)
# > 'Name is foo'
user.name = None
print("Name is ", user.name)
# > 'Name is None'
期望的输出:
user = User(name='some_name', password='some_password', email='user@example.com')
user.name = None
print("Name is ", user.name)
# > 'Name is foo'
有什么想法可以得到所需的输出吗?我认为使用getter和setter有助于解决该问题。然而,我无法在Pydantic模型中让它们起作用:
尝试实现getter和setter:
class User(BaseModel):
name: Optional[str] = ''
password: Optional[str] = ''
email: EmailStr
def get_password(self):
return self.password
def set_password(self, password):
self.password = hash_password(password)
password = property(get_password, set_password)
user = User(name='some_name', password='some_password', email='user@example.com')
# > RecursionError: maximum recursion depth exceeded
我也尝试了属性装饰器:
class User(BaseModel):
name: Optional[str] = ''
password: Optional[str] = ''
email: EmailStr
@property
def password(self):
return self._password
@password.setter
def password(self, password):
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
self._password = pwd_context.hash(password)
user = User(name='some_name', email='user@example.com')
user.password = 'some_password'
# > ValueError: "User" object has no field "password"
我还尝试重写了 init 方法:
class User(BaseModel):
name: Optional[str] = ""
password: Optional[str] = ""
email: EmailStr
def __init__(self, name, password, email):
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
password = pwd_context.hash(password)
super().__init__(name=name, password=password, email=email)
user = User(name="some_name", password="some_password", email='user@example.com')
print(user.password)
# > AYylwSnbQgCHrl4uue6kO7yiuT20lazSzK7x # Works as expected
user.password = "some_other_password"
print(user.password)
# > "some_other_password" # Does not work
user.password = None
print(user.password)
# > None # Does not work either
@validator(pre=True, always=True)
然后返回一个默认值。我使用了return v or cls.__name__.lower()
来将小写类名设置为Optional[str]
字段的默认值。 - rjurney