这是单进程顺序执行的代码：

import requests,time,os,random def img_down(url): with open("{}".format(str(random.random())+os.path.basename(url)),"wb") as fob: fob.write(requests.get(url).content) urllist=[] with open("urllist.txt","r+") as u: for a in u.readlines(): urllist.append(a.strip()) s=time.clock() for i in range(len(urllist)): img_down(urllist[i]) e=time.clock() print ("time: %d" % (e-s))

这是多进程的代码：

from multiprocessing import Pool import requests,os,time,random def img_down(url): with open("{}".format(str(random.random())+os.path.basename(url)),"wb") as fob: fob.write(requests.get(url).content) if __name__=="__main__": urllist=[] with open("urllist.txt","r+") as urlfob: for s in urlfob.readlines(): urllist.append(s.strip()) s=time.clock() p=Pool() for i in range(len(urllist)): p.apply_async(img_down,args=(urllist[i],)) p.close() p.join() e=time.clock() print ("time: {}".format(e-s))

但是单进程和多进程花费的时间几乎没区别，问题大概是requests阻塞IO，请问理解的对不对，代码该怎么修改达到多进程的目的？
谢谢！