Overview

Developed by	Guardrails AI
Date of development	Feb 15, 2024
Validator type	Format
Blog	-
License	Apache 2
Input/Output	Output

Description

This validator ensures that a generated output is in lowercase.

Installation

guardrails hub install hub://guardrails/lowercase

Usage Examples

Validating string output via Python

In this example, we’ll test that a generated sentence is lowercase.

# Import Guard and Validator
from guardrails import Guard
from guardrails.hub import LowerCase

# Setup Guard
guard = Guard().use(LowerCase, on_fail="exception")

response = guard.validate("may december")  # Validator passes

try:
    response = guard.validate("PAST LIVES")  # Validator fails
except Exception as e:
    print(e)

Output:

Validation failed for field with errors: Value PAST LIVES is not lowercase.

API Reference

__init__(self, on_fail="noop")

Initializes a new instance of the Validator class.

Parameters:

• on_fail (str, Callable): The policy to enact when a validator fails. If str, must be one of reask, fix, filter, refrain, noop, exception or fix_reask. Otherwise, must be a function that is called when the validator fails.

__call__(self, value, metadata={}) → ValidationResult

Validates the given value using the rules defined in this validator, relying on the metadata provided to customize the validation process. This method is automatically invoked by guard.parse(...), ensuring the validation logic is applied to the input data.

Note:

1. This method should not be called directly by the user. Instead, invoke guard.parse(...) where this method will be called internally for each associated Validator.
2. When invoking guard.parse(...), ensure to pass the appropriate metadata dictionary that includes keys and values required by this validator. If guard is associated with multiple validators, combine all necessary metadata into a single dictionary.

Parameters:

• value (Any): The input value to validate.
• metadata (dict): A dictionary containing metadata required for validation. No additional metadata keys are needed for this validator.