学了两天爬虫，在各种参考资料的帮助下小试牛刀，成功爬取了placekitten的猫咪图，开心。

贴上代码，有需要的自取，第一次自己写爬虫代码，虽然有点low，继续努力啊。

import urllib.request as ur
import re
import os
count = 0
def open_url(url):
    req = ur.Request(url)
    req.add_header('User-Agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 Edge/16.16299')
    response = ur.urlopen(req)
    html = response.read()
    return html
def get_pix(url):
	html = open_url(url).decode('utf-8')
	match = re.findall(r'/?\d?\d\d/\d\d\d', html)
	return match
def get_img(url, folder='cat'):
	global count
	os.mkdir(folder)
	os.chdir(folder)
	match = get_pix(url)
	for each in match:
		req = ur.Request(url+ each)
		response = ur.urlopen(req)

		count += 1
		cat_img = response.read()
		with open('cat_img' + str(count) + '.jpg', 'wb') as f:
			f.write(cat_img)
			print('cat_img' + str(count) + '.jpg下载完成')

def main():
	get_img('http://placekitten.com/')


if __name__ == '__main__':
	main()