如何使用python爬取抖音视频？

import requests

path = 'D:/video/'

num = 1788

def response(flow):

    global num

    target_urls = ['url']

    for url in target_urls:

         if flow.request.url.startswith(url):

                      filename = path + str(num) + '.mp4

            res = requests.get(flow.request.url, stream=True)

                with open(filename, 'ab') as f:

                f.write(res.content)

                f.flush()

                print(filename + '下载完成')

            num += 1