def is_article(post_links, post):
    """Checks that an article is valid and returns a bool"""

    # Return false if post is a section of today.com
    if post["href"].count("-") < 4:
        return False

    # Return False if post is a video
    elif "video" in post["href"]:
        return False

    # Return False if post is already in post_links
    elif post["href"] in post_links:
        return False

    # If all checks pass, return True
    else:
        return True