recaptcha_validator.py

try:
    from recaptcha.client import captcha
    from pylons import request, config

    class RecaptchaValidator(Schema):

        '''
        Validates ReCAPTCHA against their web service
        '''

        challenge = validators.String(not_empty=True, strip=True)
        response  = validators.String(not_empty=True, strip=True)

        def to_python(self, value, state):
            challenge = value.get('recaptcha_challenge_field', '')
            response  = value.get('recaptcha_response_field', '')
            key       = config['recaptcha_private_key']
            remoteip  = request.remote_addr

            recaptcha_response = captcha.submit(challenge, response, key, remoteip)

            if not recaptcha_response.is_valid:
                raise Invalid('Please enter the words shown', value, state)

            return value

except ImportError, e:    
    RecaptchaValidator = None