Custom Validators¶

You can add a custom validator by creating a class and inheriting from Validator (from func_validator import Validator) base class. Implement the __call__ method to accept arguments in the order arg_value and arg_name. Raise a ValidationError (from func_validator import ValidationError) if validation fails.

Example Custom Validator¶

In [10]:

# Config to have a single line output of Exception error message
import sys; sys.tracebacklimit = 0;
%xmode plain

# Config to have a single line output of Exception error message import sys; sys.tracebacklimit = 0; %xmode plain

Exception reporting mode: Plain

Imports¶

In [11]:

from typing import Annotated

from func_validator import validate_params, Validator, ValidationError

from typing import Annotated from func_validator import validate_params, Validator, ValidationError

Code Example¶

In [12]:

class MustBeEven(Validator):

    def __call__(self, arg_value, arg_name: str):
        if arg_value % 2 != 0:
            raise ValidationError(f"{arg_name}:{arg_value} must be even")

class MustBeEven(Validator): def __call__(self, arg_value, arg_name: str): if arg_value % 2 != 0: raise ValidationError(f"{arg_name}:{arg_value} must be even")

In [13]:

@validate_params
def fn(param_1: Annotated[int, MustBeEven()]):
    return param_1 * param_1

@validate_params def fn(param_1: Annotated[int, MustBeEven()]): return param_1 * param_1

In [14]:

fn(param_1=10)

fn(param_1=10)

Out[14]:

100

In [15]:

fn(param_1=11)

fn(param_1=11)

ValidationError: param_1:11 must be even