py3+requests+urllib+bs4+threading，爬取斗图图片

实现原理及思路请参考我的另外几篇爬虫实践博客

py3+urllib+bs4+反爬，20+行代码教你爬取豆瓣妹子图：http://www.cnblogs.com/UncleYong/p/6892688.html
py3+requests+json+xlwt，爬取拉勾招聘信息：http://www.cnblogs.com/UncleYong/p/6960044.html
py3+urllib+re，轻轻松松爬取双色球最近100期中奖号码：http://www.cnblogs.com/UncleYong/p/6958242.html

实现代码如下：

#-*- coding:utf-8 -*-
import requests, threading, time
from lxml import etree
from bs4 import BeautifulSoup

# 获取源码
def get_html(url):
    # url = 'http://www.doutula.com/article/list/?page=1'
    headers = {'user-agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36'}
    request = requests.get(url=url, headers=headers) # 网址发送get请求
    response = request.content.decode('utf-8') # 获取源码
    # print(response)
    return response

# 匹配图片url
def get_img_html(html):
    # soup = BeautifulSoup(html,'html.parser')
    soup = BeautifulSoup(html,'lxml') # 解析网页
    all_a = soup.find_all('a',class_='list-group-item') # 获取a标签，如果有class或id来命名，一定要加上名字
    # class="list-group-item"是a标签的名字
    # <a class="list-group-item" href="http://www.doutula.com/article/detail/7536783">
    # print(type(all_a)) # <class 'bs4.element.ResultSet'>
    # print(all_a)
    for i in all_a:
        # print(i['href'])
        img_html = get_html(i['href']) # 获取内页源码，i['href']表示获取属性值
        # print(img_html)
        get_img(img_html)

# 获取图片url
def get_img(html):
    # soup = etree.HTML(html) # 初始化源码
    # items = soup.xpath('//div[@class="artile_des"]') # //表示某个目录下,从匹配选择的当前节点选择文档中的节点，而不考虑它们的位置。
    # # []表示过滤条件
    # for item in items:
    #     imgurl_list = item.xpath('table/tbody/tr/td/a/img/@onerror')
    #     # print(imgurl_list)
    #     # start_save_img(imgurl_list)
    soup = BeautifulSoup(html, 'lxml')
    items = soup.find('div',class_='swiper-slide').find_all('div',class_='artile_des')
    # 不能写成这样：find_all后面不能跟find，因为find是找一个，find_all是找多个，从多个中找一个是不对的
    # items = soup.find('div',class_='swiper-slide').find_all('div',class_='artile_des').find('img')['src']
    # print(items)
    imgurl_list = []
    for i in items:
        imgurl = i.find('img')['src'] # img标签下的src属性
        # print(type(imgurl)) # <class 'str'>
        # print(imgurl)
        imgurl_list.append(imgurl)
    start_save_img(imgurl_list) # 这里是对每一组套图做多线程


# 下载图片
x = 1
def save_img(img_url):
    # global x # 全局变量
    # x +=1
    # img_url = img_url.split('=')[-1][1:-2].replace('jp','jpg') # 以=分割
    # print('正在下载'+'http:'+img_url)
    # img_content = requests.get('http:'+img_url).content
    # with open('doutu/%s.jpg'%x, 'wb')  as f:# urllib下的retrieve也可以下载
    #     f.write(img_content)
    global x # 全局变量
    x +=1


    print('正在下载：'+img_url)
    geshi = img_url.split('.')[-1]  # 因为图片格式不一样，所以切片，把链接中图片后缀获取到，用于下面拼接文件名
    img_content = requests.get(img_url).content
    with open('doutu/%s.%s'%(x,geshi), 'wb')  as f: # urllib下的retrieve也可以下载
        f.write(img_content)

def start_save_img(imgurl_list):
    for i in imgurl_list:
        # print(i)
        th = threading.Thread(target=save_img,args=(i,)) # i后面加逗号表示args是一个元组
        # target是可调用对象，是一个函数名，线程启动后执行，
        th.start()
        th.join()

# 主函数
def main():
    start_url = 'http://www.doutula.com/article/list/?page={}'
    for i in range(1,2):
        # print(start_url.format(i))
        start_html = get_html(start_url.format(i))
        get_img_html(start_html) # 获取内页图片的url

if __name__ == '__main__': # 判断文件入口
    start_time = time.time()
    main()
    end_time = time.time()
    print(start_time)
    print(end_time)
    print(end_time-start_time)