新手有关于bs4 requests爬虫问题

要求爬取https://turnoff.us的漫画
# -*- coding:utf-8 -*-
import requests
import os
import bs4
url = "https://turnoff.us"
os.makedirs("漫画",True)

while not url.endswith('.prev href[previous]'):
    web = requests.get(url)
    web.raise_for_status()
    web_soup = bs4.BeautifulSoup(web.text)
    comics = web_soup.select('.post-content img[src]')
    if comics == []:
        print("no comic exists")
        continue

comics_linkage = comics[0].get("src")
comics_content = requests.get("https://turnoff.us" +comics_linkage)
comics_content.raise_for_status()
disk_file = os.path.join("漫画",os.path.basename(comics_linkage))
with open(disk_file,"wb") as f:
    for i in comics_content.iter_content(100000):
        f.write(i)
    f.close()

prevs = web_soup.select('.prev a[href]')
if prevs ==[]:
    print("cannot get prev linkage")

url = "http://turnoff.us/"+prevs[0].get('href')
哪里出了问题，创建文件夹内是空的，爬不到图片