CODEWITHSUNDEEP
pythonpython-3.xpydantic
FranmR
FranmR

Reputation: 76

Filter the use of validator for certain values

Is it possible to just execute a validator for a certain value? Let's say I have the following case, where I have a class with two boolean fields and I use a validator to make sure that field1 can't be True when field2 is set to True:

from pydantic import BaseModel, validator


class MyClass(BaseModel):
    field1: bool
    field2: bool

    @validator('field2')
    def both_fields_are_true(cls, v, values):
        field1 = values.get('field1')
        if field1 and field2:
            raise ValueError
        return v

myClass = MyClass(field1=True, field2=False)

The instance myClass will run the validator, but it is not needed as the second field is set to False, and then, the validation does not make sense anymore.

How can I avoid my class from executing the validation in such a case like that? I know the result will be the same anyway, but it is good to avoid executing things when they're not needed.

Upvotes: 1

Views: 527

Answers (1)

funnydman
funnydman

Reputation: 11346

You can use @root_validator, which is performed on the entire model's data:

class MyClass(BaseModel):
    field1: bool
    field2: bool

    @root_validator
    def both_fields_are_true(cls,  values):
        field1, field2 = values.get('field1'), values.get('field2')
        if field1 and field2:
            raise ValueError('Both fields are true')
        return values


myClass = MyClass(field1=True, field2=False)

Upvotes: 1

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