为什么会出错？？？

import re
import requests as r
import pymongo as pmg

client = pmg.MongoClient('localhost', 27017)
mydb = client['mydb']
b = mydb['编程论坛-python']
g = b.insert_one
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit\
/537.36(KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36'
}

def get_urls_and_titles(url):
    html = r.get(url, headers=headers).text
    urls = re.findall('<a href="(.*?)" title="发帖时间：', html)
    titles = re.findall('<a href="thread-.*?">(.*?)</a>', html)
    urls = sets(urls)
    for i in range(4):
        del titles[1]
    titles = tuple(titles)
    write((titles, urls, ('title', 'url')))
def sets(things):
    a = set(things)
    a = tuple(a)
    return a
def write(*args):
    for each in args:
        for infos1, infos2, info3 in each[0], each[1], each[2]:
            for info1, info2 in infos1, infos2:
                info = {
                    info3[0]: info1,
                    info3[1]: info2
                    }
                g(info)

if __name__ == '__main__':
    get_urls_and_titles('http://bbs.bccn.net/forum-246-1.html')