从url下载文件（在列表中）

我正在抓取google以获取pdf文件（白皮书），并希望将它们另存为文件，而不是在控制台中列出。

这是我目前拥有的代码：

import  requests, re
from    docopt import docopt
from    bs4 import BeautifulSoup
from    time import time as timer
from urllib.request import urlopen, urlretrieve, quote
from urllib.parse import urljoin

def get_urls(search_string, start):
    #Empty temp List to store the Urls
    temp        = []
    url         = 'https://www.google.com/search'
    payload     = { 'q' : search_string, 'start' : start }
    my_headers  = { 'User-agent' : 'Mozilla/11.0' }
    r           = requests.get( url, params = payload, headers = my_headers )
    soup        = BeautifulSoup( r.text, 'html.parser' )
    h3tags      = soup.find_all( 'h3', class_='r' )
    for h3 in h3tags:
        try:
            temp.append( re.search('url\?q=(.+?)\&sa', h3.a['href']).group(1) )
        except:
            continue
    return temp

def main():
    start     = timer()
    #Empty List to store the Urls
    result    = []
    arguments = docopt( __doc__, version='MakMan Google Scrapper & Mass Exploiter' )
    search    = arguments['<search>']
    pages     = arguments['<pages>']
    #Calling the function [pages] times.
    for page in range( 0,  int(pages) ):
        #Getting the URLs in the list
        result.extend( get_urls( search, str(page*10) ) )
    #Removing Duplicate URLs
    result    = list( set( result ) )
    print( *result, sep = '\n' )
    print( '\nTotal URLs Scraped : %s ' % str( len( result ) ) ) 
    print( 'Script Execution Time : %s ' % ( timer() - start, ) ) 
if __name__ == '__main__':
    main()


#End

我尝试添加：

with open ('file.txt', 'w') as f:
   print( *result, file=f)   

最后将其解析为文件，但是我敢肯定，有一种下载pdf文件的简便方法，而无需先将链接保存到文件中。