使用XPath的爬虫,百度贴吧图片下载

现在我们用XPath来做一个简单的爬虫，我们尝试爬取某个贴吧里的所有帖子，并且将该这个帖子里每个楼层发布的图片下载到本地。

#!/usr/bin/env python
# -*- coding:utf-8 -*-

import urllib
import urllib2
from lxml import etree

def loadPage(url):
    """
        作用：根据url发送请求，获取服务器响应文件
        url: 需要爬取的url地址
    """
    #print url
    #headers = {"User-Agent" : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_0) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11"}

    request = urllib2.Request(url)
    html = urllib2.urlopen(request).read()
    # 解析HTML文档为HTML DOM模型
    content = etree.HTML(html)
    #print content
    # 返回所有匹配成功的列表集合
    link_list = content.xpath('//div[@class="threadlist_lz clearfix"]/div/a/@href')
    for link in link_list:
        fulllink = "http://tieba.baidu.com" + link
        # 组合为每个帖子的链接
        #print link
        loadImage(fulllink)

# 取出每个帖子里的每个图片连接
def loadImage(link):
    headers = {"User-Agent" : "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36"}
    request = urllib2.Request(link, headers = headers)
    html = urllib2.urlopen(request).read()
    # 解析
    content = etree.HTML(html)
    # 取出帖子里每层层主发送的图片连接集合
    link_list = content.xpath('//img[@class="BDE_Image"]/@src')
    # 取出每个图片的连接
    for link in link_list:
        #print link
        writeImage(link)

def writeImage(link):
    """
        作用：将html内容写入到本地
        link：图片连接
    """
    #print "正在保存 " + filename
    headers = {"User-Agent" : "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36"}
    # 文件写入
    request = urllib2.Request(link, headers = headers)
    # 图片原始数据
    image = urllib2.urlopen(request).read()
    # 取出连接后10位做为文件名
    filename = link[-10:]
    # 写入到本地磁盘文件内
    with open(filename, "wb") as f:
        f.write(image)
    print "已经成功下载 "+ filename

def tiebaSpider(url, beginPage, endPage):
    """
        作用：贴吧爬虫调度器，负责组合处理每个页面的url
        url : 贴吧url的前部分
        beginPage : 起始页
        endPage : 结束页
    """
    for page in range(beginPage, endPage + 1):
        pn = (page - 1) * 50
        fullurl = url + "&pn=" + str(pn)
        #print fullurl
        loadPage(fullurl)
        #print html

        print "谢谢使用"

if __name__ == "__main__":
    kw = raw_input("请输入需要爬取的贴吧名:")
    beginPage = int(raw_input("请输入起始页："))
    endPage = int(raw_input("请输入结束页："))

    url = "http://tieba.baidu.com/f?"
    key = urllib.urlencode({"kw": kw})
    fullurl = url + key
    tiebaSpider(fullurl, beginPage, endPage)

 在python3中使用XPath的爬虫,百度贴吧图片下载：

import requests
from lxml import etree
from urllib import parse

def loadPage(url):
    """
        作用：根据url发送请求，获取服务器响应文件
        url: 需要爬取的url地址
    """
    #print url
    #headers = {"User-Agent" : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_0) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11"}

    response = requests.get(url)
    html = response.content
    # 解析HTML文档为HTML DOM模型
    content = etree.HTML(html)
    #print content
    # 返回所有匹配成功的列表集合
    link_list = content.xpath('//div[@class="threadlist_lz clearfix"]/div/a/@href')
    for link in link_list:
        fulllink = "http://tieba.baidu.com" + link
        # 组合为每个帖子的链接
        #print(link)
        loadImage(fulllink)

# 取出每个帖子里的每个图片连接
def loadImage(link):
    headers = {"User-Agent" : "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36"}
    response = requests.get(link, headers = headers)
    html = response.content
    # 解析
    content = etree.HTML(html)
    # 取出帖子里每层层主发送的图片连接集合
    link_list = content.xpath('//img[@class="BDE_Image"]/@src')
    # 取出每个图片的连接
    for link in link_list:
        #print(link)
        writeImage(link)

def writeImage(link):
    """
        作用：将html内容写入到本地
        link：图片连接
    """
    #print "正在保存 " + filename
    headers = {"User-Agent" : "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36"}
    # 文件写入
    response = requests.get(link, headers = headers)
    # 图片原始数据
    #image = urllib2.urlopen(request).read()
    image = response.content
    # 取出连接后10位做为文件名
    filename = link[-10:]
    # 写入到本地磁盘文件内
    with open(filename, "wb") as f:
        f.write(image)
    print("已经成功下载 "+ filename)

def tiebaSpider(url, beginPage, endPage):
    """
        作用：贴吧爬虫调度器，负责组合处理每个页面的url
        url : 贴吧url的前部分
        beginPage : 起始页
        endPage : 结束页
    """
    for page in range(beginPage, endPage + 1):
        pn = (page - 1) * 50
        fullurl = url + "&pn=" + str(pn)
        #print(fullurl)
        loadPage(fullurl)
        #print(html)

        print("谢谢使用")

if __name__ == "__main__":
    kw = input("请输入需要爬取的贴吧名:")
    beginPage = int(input("请输入起始页："))
    endPage = int(input("请输入结束页："))
    url = "http://tieba.baidu.com/f?"
    #key = urllib.urlencode({"kw": kw})
    key = parse.urlencode({"kw": kw})
    fullurl = url + key
    tiebaSpider(fullurl, beginPage, endPage)