get search bot in django

See this python code

def _is_searchbot(request):
    user_agent = request.META.get('HTTP_USER_AGENT', None)
    if not user_agent:
        return False
    parts = re.findall(r'([\w\-\s\.]*(yandex|google)[\w\-\s\.]*)', user_agent)
    if not parts:
        return False
    part = parts[0]
    if part not in _SEARCH_BOTS:
        return False
    return True

_SEARCH_BOTS = [
    ('yandex.com', 'yandex'),
    ('www.yandex.com', 'yandex'),
    ('yandex.ru', 'yandex'),
    ('www.yandex.ru', 'yandex'),
    ('www.google.com', 'google'),
    ('google.com', 'google'),
    ('www.google.ru', 'google'),
    ('google.ru', 'google'),
]