Python爬虫之网页图片抓取的方法

__author__ = "JentZhang"
import urllib.request
import os
import random
import re
def url_open(url):
  '''
  打开网页
  :param url:
  :return:
  '''
  req = urllib.request.Request(url)
  req.add_header('User-Agent',
          'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.75 Safari/537.36')
  # 应用代理
  '''
  proxyies = ["111.155.116.237:8123","101.236.23.202:8866","122.114.31.177:808"]
  proxy = random.choice(proxyies)
  proxy_support = urllib.request.ProxyHandler({"http": proxy})
  opener = urllib.request.build_opener(proxy_support)
  urllib.request.install_opener(opener)
  '''
  response = urllib.request.urlopen(url)
  html = response.read()
  return html
def save_img(folder, img_addrs):
  '''
  保存图片
  :param folder: 要保存的文件夹
  :param img_addrs: 图片地址（列表）
  :return:
  '''
  # 创建文件夹用来存放图片
  if not os.path.exists(folder):
    os.mkdir(folder)
  os.chdir(folder)
  for each in img_addrs:
    filename = each.split('/')[-1]
    try:
      with open(filename, 'wb') as f:
        img = url_open("http:" + each)
        f.write(img)
    except urllib.error.HTTPError as e:
      # print(e.reason)
      pass
  print('完毕！')
def find_imgs(url):
  '''
  获取全部的图片链接
  :param url: 连接地址
  :return: 图片地址的列表
  '''
  html = url_open(url).decode("utf-8")
  img_addrs = re.findall(r'src="(.+?\.gif)', html)
  return img_addrs
def get_page(url):
  '''
  获取当前一共有多少页的图片
  :param url: 网页地址
  :return:
  '''
  html = url_open(url).decode('utf-8')
  a = html.find("current-comment-page") + 23
  b = html.find("]</span>", a)
  return html[a:b]
def download_mm(url="http://jandan.net/ooxx/", folder="OOXX", pages=1):
  '''
  主程序（下载图片）
  :param folder:默认存放的文件夹
  :param pages: 下载的页数
  :return:
  '''
  page_num = int(get_page(url))
  for i in range(pages):
    page_num -= i
    page_url = url + "page-" + str(page_num) + "#comments"
    img_addrs = find_imgs(page_url)
    save_img(folder, img_addrs)
if __name__ == "__main__":
  download_mm()