python使用gevent实现并发下载器

并发下载原理

import gevent
from gevent import monkey
import urllib.request

monkey.patch_all()

def my_download(url):
        print('GET: %s' % url)
        resp = urllib.request.urlopen(url)
        data = resp.read()
        print('%d bytes received from %s.' % (len(data), url))

gevent.joinall([
        gevent.spawn(my_download, "https://www.baidu.com"),
        gevent.spawn(my_download, "https://www.cnblogs.com"),
        gevent.spawn(my_download, "https://www.huya.com")

])

运行结果：

GET: https://www.baidu.com
GET: https://www.cnblogs.com
GET: https://www.huya.com
227 bytes received from https://www.baidu.com.
46411 bytes received from https://www.cnblogs.com.
353563 bytes received from https://www.huya.com.

实现多张图片同时下载

import gevent
from gevent import monkey
import urllib.request

monkey.patch_all()

def my_download(url, image_path):
	print('GET: %s' % url)
	resp = urllib.request.urlopen(url)
	data = resp.read()
	print('%d bytes received from %s.' % (len(data), url))

	with open(image_path, "wb") as f:
		f.write(data)

gevent.joinall([
	gevent.spawn(my_download, "https://huyaimg.msstatic.com/cdnimage/anchorpost/1099/4c/73ff3e6ce165fb658b2082d4d126c6_2168_1544414129.jpg", "1.jpg"),
	gevent.spawn(my_download, "https://huyaimg.msstatic.com/cdnimage/anchorpost/1020/03/7949816c55f45b9adc9f03d9330af3_2168_1542941499.jpg", "2.jpg"),
	gevent.spawn(my_download, "https://huyaimg.msstatic.com/cdnimage/anchorpost/1061/55/8071537fa10120c43c5a1359a88530_2168_1545302709.jpg", "3.jpg"),
])