"""

对html文本的解析方案-示例：在标签开始的时候检查标签中的attrs属性，解析出所有的参数的href属性值

依赖安装：pip install sgmllib3k

使用方法：

    1.自定义一个类，继承sgmllib的SGMLParser

    2.复写SGMLParser的方法，添加自己自定义的标签处理函数

    3.通过自定义的类的对象的.feed(data)把要解析的数据传入解析器，然后自定义的方法自动生效。

"""

from urllib import request

import sgmllib

class HandleHtml(sgmllib.SGMLParser):

    """

    自定义HTML解析类

    """

    def unknown_starttag(self, tag, attrs):

        """

        任意标签开始被解析时调用

        :param tag: 标签名

        :param attrs: 标签的参数

        :return:

        """

        try:

            for attr in attrs:

                if attr[0] == 'href':

                    print(f"{attr[0]}:{attr[1]}")

        except:

            pass

if __name__ == '__main__':

    response = request.urlopen("http://freebuf.com/")

    page = response.read()

    page = page.decode('utf-8')

    # 创建HTML解析对象

    handle_html = HandleHtml()

    # 将数据传入解析器

    handle_html.feed(page)

href:https://www.freebuf.com/buf/plugins/wp-favorite-posts/wpfp.css

href:https://static.3001.net/css/recentcomments/wp-recentcomments.css?ver=2.2.3

href:https://www.freebuf.com/buf/plugins/gold/assets/css/widget.css?ver=1.3.2.1

href:https://static.3001.net/css/highslide/highslide.css

href:https://www.freebuf.com/buf/plugins/cartpauj-pm/style/style.css

href: https://www.freebuf.com/buf/plugins/simditor/highlight/styles/default.css

href:https://static.freebuf.com/images/favicon.ico

href:https://static.3001.net/css/new/header.css

href:https://static.3001.net/css/new/bootstrap.min.css?ver=2016051701

href:https://static.3001.net/css/new/swiper-3.4.2.min.css

href:https://static.3001.net/css/new/model.css?ver=2017112156855

href:https://static.3001.net/css/new/style.css?ver=2018112123749359438534

href:http://www.freebuf.com

href:http://www.freebuf.com

href:http://job.freebuf.com

href:#

......