class article:
    def __init__(self, title="", content=""):
        self.title = title
        self.content = content
        self.keywords = []
        self.weight = 0.0

    def jsonify(self):
        d = {}
        d["title"] = self.title
        d["content"] = self.content
        d["keywords"] = self.keywords
        d["weight"] = self.weight
        return d

    def __str__(self):
        return str(self.jsonify())

    def __repr__(self):
        return str(self.jsonify())

    def summary(self):
        return "{0:20.20}, {1:5.5}, {2}".format(self.title, self.weight, self.keywords)

    def replace_keywords(self, keywords=[]):
        self.keywords = keywords

    def get_content(self):
        return self.content


class article_list:
    def __init__(self, articles: list = []):
        self.list = articles

    def sort(self):
        sorted(self.list, key=compare(lambda item1, item2: item1.weight < item2.weight))

    def append(self, art: article):
        self.list.append(art)

    def __str__(self):
        return str("\n".join([x.summary() for x in self.list]))