def get_domain_url(url):
    """
    Use this to convert a url like this:
    https://blog.xkcd.com/2014/07/22/what-if-book-tour/
    Into this:
    https://blog.xkcd.com
    """
    if not url.startswith("http://") and not url.startswith("https://"):
        return url
    url_header = url.split("://")[0]
    simple_url = url.split("://")[1]
    base_url = simple_url.split("/")[0]
    domain_url = url_header + "://" + base_url
    return domain_url