Я просто использую этот клиент Python для recaptcha:
http://pypi.python.org/pypi/recaptcha-client
тогда мой взгляд выглядит так:
captcha_key = get_config('RECAPTCHA_PUB_KEY',None)
recaptcha_challenge_field = request.POST.get('recaptcha_challenge_field', None)
recaptcha_response_field = request.POST.get('recaptcha_response_field', None)
check_captcha = captcha.submit(recaptcha_challenge_field, recaptcha_response_field, settings.RECAPTCHA_PRIVATE_KEY, request.META['REMOTE_ADDR'])
if check_captcha.is_valid is False:
log.info('captcha_error : %s' % check_captcha.error_code)
return {'TEMPLATE':template_name,'captcha_error': True,'register_form': f,'captcha_key':captcha_key ,'next':redirect_to}