Let's say I have a simple pydantic.BaseModel like this:
from myapp import User
from pydantic import BaseModel, validator
class ChangePasswordRequest(BaseModel):
class Config:
arbitrary_types_allowed = True # because I'm using my `User` arbitrary type
user: User
current_password: constr(min_length=1, max_length=255)
new_password: constr(min_length=8, max_length=64)
@validator("user")
def user_is_active(cls, user: User):
assert not user.inactive, "User is not active."
return user
@validator("current_password")
def current_password_validator(cls, password: str, values: Dict[str, Any]):
user: User = values["user"]
assert user.check_password(password), "current_password is not valid."
return password
This is the model I'd like to use to handle user's password change. When I create ChangePasswordRequest with inactive user, I get a KeyError, because pydatinc validates all the fields.
from myapp import User
user = User(inactive=True)
r = ChangePasswordRequest(user=user, current_password="current", new_password="new-password")
# I get
KeyError: 'user'
The reason why it happens:
user_is_activeis called and validation fails.values["user"]is not set as an effectcurrent_password_validatoris called.values["user"]key does not exist andKeyErroris raised.
What I want to achieve is to skip all validation if user field validation fails as there is no point of further validation. This is not a problem for a small model like mine as I can add an if statement in each validator, but this gets annoying as model grows.
@validator("current_password")
def current_password_validator(cls, password: str, values: Dict[str, Any]):
if not user := values.get("user"):
return password
assert user.check_password(password), "current_password is not valid."
return password
Other way would be to use root_validator(pre=True), but there is another problem with this approach. Error is located in the __root__ field, instead of user field.
@root_validator(pre=True)
def user_is_active(cls, values: Dict[str, Any]):
user: Union[User, None] = values.get("user", None)
assert getattr(user, "is_active", False), "User is not active."
return values
# which produces following error:
[{'loc': ['__root__'],
'msg': 'User is not active.',
'type': 'assertion_error'}]
Does pydantic have any feature that will stop further validation if one of the "main" or "crucial" fields fails?