066 用多线程从网上下载图像文件

在urls.txt文件中包含了若干个图像url，一行一个url，请使用多线程下载这些图像文件，并按url出现的顺序保存为0.jpg、1.jpg、2.jpg，依次类推。

from urllib3 import *
import threading

http = PoolManager()
disable_warnings()

f = open('urls.txt', 'r')
urlList = []
while True:
    url = f.readline()
    if url == '':
        break
    urlList.append(url.strip())
f.close()

print(urlList)

class DownloadThread(threading.Thread):
    def __init__(self, func, args):
        super().__init__(func, args)

def donwload(filename, url):
    response = http.request('GET', url)
    f = open(filename, 'wb')
    f.write(response.data)
    f.close()
    print('<', url, '>', '下载完成')

for i in range(len(urlList)):
    thread = DownloadThread(donwload, (str(i) + '.jpg', urlList[i]))
    thread.start()