python_多線程下載文件

一、多線程下載文件

import requests,time,threading
from hashlib import md5
result = {}
def down_load_pic(url):
    req = requests.get(url)
    m = md5(url.encode())
    with open( m.hexdigest()+'.png','wb') as fw:
        fw.write(req.content)

url_list = ['http://www.nnzhp.cn/wp-content/uploads/2019/10/f410afea8b23fa401505a1449a41a133.png',
            'http://www.nnzhp.cn/wp-content/uploads/2019/11/481b5135e75c764b32b224c5650a8df5.png',
            'http://www.nnzhp.cn/wp-content/uploads/2019/11/b23755cdea210cfec903333c5cce6895.png',
            'http://www.nnzhp.cn/wp-content/uploads/2019/11/542824dde1dbd29ec61ad5ea867ef245.png']

#單線程下載
# start_time = time.time()
# for url in url_list:
#     down_load_pic(url)
# end_time = time.time()
# print(end_time - start_time)

#多線程下載
start_time = time.time()
for url in url_list:
    t = threading.Thread(target=down_load_pic,args=(url,))
    t.start()
while threading.activeCount() !=1:
    pass
end_time = time.time()
print(end_time - start_time)