快速获取某方向研究重要文献并批量下载

import requestsfrom bs4 import BeautifulSoupimport os
path="/xxxx/download_papter/result"if os.path.exists(path) == False:  os.mkdir(path)f = open("doi.txt", "r", encoding="utf-8")head = {'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36'}for line in f.readlines():  line = line[:-1]  url = "https://www.sci-hub.ren/" + line + "#"  try:    download_url = ""      r = requests.get(url, headers = head)    r.raise_for_status()    r.encoding = r.apparent_encoding    soup = BeautifulSoup(r.text, "html.parser")    if soup.iframe == None:        download_url = "https:" + soup.embed.attrs["src"]     else:      download_url = soup.iframe.attrs["src"]    print(line + "t正在下载n下载链接为t" + download_url)    download_r = requests.get(download_url, headers = head)    download_r.raise_for_status()    with open(path + line.replace("/","_") + ".pdf", "wb+") as temp:      temp.write(download_r.content)  except:    with open("error.log", "a+") as error:      error.write(line + "t下载失败!n")      if "https://" in download_url:        error.write(" 下载url链接为: " + download_url + "nn")  else:    download_url = ""     print(line + "t文献下载成功.n")f.close()