python下载器

from urllib import request #urllib数据，爬虫二 #resquest请求resquest
from multiprocessing import Process
import os
def downloader(url,**kwargs): # downloader下载器downloader
#arg元组元组里只有一个元素也要加逗号
print(‘当前进程’,os.getpid(),end=’’)
print(‘父进程’,os.getppid())#getppid()获得父进程
#print(‘关键字参数’,kwargs[‘pro’])
#文件名将图片保存
# file_name=url.split(’/’)[-1]
# response=request.urlopen(url)#网络请求#响应一个对象
# content=response.read()#获取相应的内容
# with open(file_name,‘wb’) as fq:#保存
# fq.write(content)
if name == ‘main’:
# for i in range(1,5,1):
# url=‘http://www.langlang2017.com/img/banner’+str(i)+’.png’
# print(url)
# p=Process(target=downloader(url,))
# p.start()#开始下载
urlList=[
‘http://www.langlang2017.com/img/banner’+str(1)+’.png’,
‘http://www.langlang2017.com/img/banner’ + str(2) + ‘.png’,
# ‘http://www.langlang2017.com/img/banner’ + str(3) + ‘.png’,
# ‘http://www.langlang2017.com/img/banner’ + str(4) + ‘.png’
]
nameList=[‘进程一’,‘进程二’]
i=0
pList=[]
for url in urlList:
n=nameList[i]
#p=Process(target=downloader(url,))
p=Process(target=downloader,name=n,args=(url,),kwargs={‘pro’:‘关键字参数’})
print(‘子进程%s将被运行’%n)
p.start()
pList.append§
i+=1
for i in pList:
i.join()
print(‘主进程’,os.getpid())#getpid()获得当前进程号

print('进程已结束')