网络爬虫初试

爬取腾讯漫画的一个例子

# encoding: utf-8

from __future__ import print_function
from __future__ import unicode_literals
import requests
import base64
import re
import json
import os


requestSession = requests.session()

def getId(url):
    numRE = re.compile(r'\d+')#r的意思是不转义，即\表示原样的\。否则有可能被视图按\d为一个字符解析转义。
    id = numRE.findall(url)[0]
    return id   

def getContent(id):
    getComicInfoUrl = 'http://m.ac.qq.com/GetData/getComicInfo?id={}'.format(id)
    getComicInfo = requestSession.get(getComicInfoUrl)
    comicInfoJson = getComicInfo.text
    comicInfo = json.loads(comicInfoJson)
    comicName = comicInfo['title']#解析出漫画名
    getChapterListUrl = 'http://m.ac.qq.com/GetData/getChapterList?id={}'.format(id)
    getChapterList = requestSession.get(getChapterListUrl)
    contentJson = json.loads(getChapterList.text)
    count = contentJson['length']#获得章节数
    sortedContentList = []

    #按顺序整理章节
    for i in range(count + 1):
        for item in contentJson:
            if isinstance(contentJson[item], dict) and contentJson[item]['seq'] == i:
                sortedContentList.append({item: contentJson[item]})
                break
    return (comicName, count, sortedContentList)

def getImgList(contentJson, id):
    #cid = contentJson.keys()[0] #原作者使用的是Python2
    #在python2.x中，dict.keys()返回一个列表，在python3.x中，dict.keys()返回一个dict_keys对象，比起列表，这个对象的行为更像是set，所以不支持索引的。解决方案：list(dict.keys())[index]
    cid = list(contentJson.keys())[0]
    #getPicHashURL = 'http://m.ac.qq.com/View/mGetPicHash?id={}&cid={}'.format(id, cid) #原作者请求失效
    #getPicHashURL='http://m.ac.qq.com/chapter/index/id/{}/cid/{}'.format(id,cid) #异步加载,修改后仍是错误的
    picJsonPage = requestSession.get(getPicHashURL).text
    picJson = json.loads(picJsonPage)
    count = picJson['pCount']    #统计图片数量
    pHash = picJson['pHash']
    sortedImgDictList = []
    for i in range(1, count + 1):
        for item in pHash:
            if pHash[item]['seq'] == i:
                sortedImgDictList.append(pHash[item])
                break
    imgList = []
    for imgDict in sortedImgDictList:
        k = imgDict['cid']
        m = imgDict['pid']
        j = int(id)
        uin = max(j + k + m, 10001)
        l = [j % 1000 / 100, j % 100, j, k]
        n = '/mif800/' + '/'.join(str(j) for j in l) + '/'
        h = str(m) + '.mif2'
        g="http://ac.tc.qq.com/store_file_download?buid=15017&uin="+str(uin)+"&dir_path="+n+"&name="+h
        imgList.append(g)
    return imgList

def downloadImg(imgUrlList, contentPath):
    count = len(imgUrlList)
    print('该集漫画共计{}张图片'.format(count))
    i = 1
    for imgUrl in imgUrlList:
        print('\r正在下载第{}张图片...'.format(i), end='')
        imgPath = os.path.join(contentPath, '{0:0>3}.jpg'.format(i))
        downloadRequest = requestSession.get(imgUrl, stream=True)
        with open(imgPath, 'wb') as f:
            for chunk in downloadRequest.iter_content(chunk_size=1024): 
                if chunk: # filter out keep-alive new chunks
                    f.write(chunk)
                    f.flush()
        i += 1
    print('完毕!\n')

def main():
    url = 'http://m.ac.qq.com/comic/index/id/623622'  #要爬取的漫画首页
    path = 'E:\\WorkSpace\\test'   #下载图片存放路径

    if not os.path.isdir(path):
        os.mkdir(path)
    id = getId(url)
    comicName,count,contentList = getContent(id)
    contentNameList = []
    for item in contentList:
        for k in item:
            contentNameList.append(item[k]['t'])
    print('漫画名: {}'.format(comicName))
    print('章节数: {}'.format(count))
    print('章节列表:')
    print('\n'.join(contentNameList))
    comicPath = os.path.join(path, comicName)
    if not os.path.isdir(comicPath):
        os.mkdir(comicPath)
    print()
    i = 0
    for content in contentList:
        print('正在下载第{0:0>4}话: {1}'.format(i + 1, contentNameList[i]))
        contentPath = os.path.join(comicPath, '第{0:0>4}话-{1}'.format(i + 1, contentNameList[i]))
        if not os.path.isdir(contentPath):
            os.mkdir(contentPath)
        imgList = getImgList(content, id)
        downloadImg(imgList, contentPath)
        i += 1

if __name__ == '__main__':
    main()

#coding=utf-8
#破解采集图片数据
"""
http://api.yyhao.com/app_api/v3/getcomicinfo/?comic_id=27284      #获得目录信息
"""
import requests
import base64
import re
import json
import os
import urllib

#获取网页源代码
def getHtmlText(url):
    try:
        head={}
        head['User-Agent'] ="Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36"
        r=requests.get(url,headers=head)
        r.raise_for_status()#如果状态不是200,引发HTTPError异常
        r.encoding=r.apparent_encoding
        return r.text   
    except:
        print("获取网页产生异常")  

#获取漫画信息
def getComicInfo(comicId):
    url='http://api.yyhao.com/app_api/v3/getcomicinfo/?comic_id={}'.format(comicId)
    info=json.loads(getHtmlText(url))
    comicName=info['comic_name']
    comicAuthor=info['comic_author']
    comicDesc=info['comic_desc']
    chapterList=info['comic_chapter'][1]['chapter_list']
    return(comicName,comicAuthor,comicDesc,chapterList)

#下载某个url对应的图片
def downloadImag(url,picPath,num):
    head={}
    head['User-Agent'] ="Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36"
    image = requests.get(url,headers=head)
    if image.status_code == 200:
        picPath=picPath+str(num)+'.jpg'
        f=open(picPath, 'wb')
        f.write(image.content)  
        f.close()
    else:
        print("下载图片出错!")

#下载一部漫画所有的图片
def downloadAll(path,chapterList):
    for chapter in chapterList:
        chapterPath=path+chapter['chapter_name']+'/'
        if not os.path.exists(chapterPath):
            os.mkdir(chapterPath)
        start=chapter['chapter_source'][0]['start_num']
        end=chapter['chapter_source'][0]['end_num']
        ofDomain=chapter['chapter_source'][0]['chapter_domain']
        if ofDomain=='':
            domain='mhpic.samanlehua.com'
        else:
            domain='mhpic.'+ofDomain
        rule=urllib.parse.quote(chapter['chapter_source'][0]['rule'])
        imageUrl='http://'+domain+rule
        imageUrl=imageUrl.replace("%24%24",'{}')
        #imageUrl=urllib.parse.quote(imageUrl)
        while(start<=end):
            imageUrlAll=imageUrl.format(start)#+'-kmw.middle'
            downloadImag(imageUrlAll,chapterPath,start)
            start+=1
        print(chapter['chapter_name']+"  has downloaded")

if __name__ == '__main__':
    comicId=3130   
    comicName,coimcAuthor,comicDesc,chapterList=getComicInfo(comicId)
    print(comicName+'  downloading...')
    #存放路径
    path='E:/WorkSpace/comic/'+comicName+'/'
    if not os.path.exists(path):
        os.mkdir(path)
    downloadAll(path,chapterList)
    print("All finished!")

其他资料
www.manhuagui.com的网站是动态加载的,用静态提取的方法失败了
参考博客
[1]http://blog.sina.com.cn/s/blog_700376570102x80k.html #scrapy静态抓取
[2]http://blog.sina.com.cn/s/blog_700376570102x8er.html
[3]http://blog.sina.com.cn/s/blog_700376570102x96k.html #动态抓取
对于数据来说，我们通常的做法就是进行Ajax处理，即异步请求数据，然后局部渲染生成整个网页。因此，我们设想，它是不是有ajax请求呢，
让我们来看看Network tab页下面查不查得到相关信息

使用PantomJS

#coding=utf-8
from selenium import webdriver
import time
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities

#基于PhantomJS创建一个浏览器，并且设置一下用户代理，否则可能出现界面不兼容的情况
dcap = dict(DesiredCapabilities.PHANTOMJS)  
dcap["phantomjs.page.settings.userAgent"] = ("Mozilla/4.0 (compatible; MSIE 5.5; windows NT)"  )  
browser = webdriver.PhantomJS(desired_capabilities=dcap)

#打开动漫的第一页
browser.get("http://ac.qq.com/ComicView/index/id/539443/cid/1")

#通过该循环，我们可以依次进行自动滑动，模拟滑动后自然会触发后续的图片资源。
for i in range(10):
    js='window.scrollTo('+str(i*1280)+','+str((i+1)*1280)+')'
    browser.execute_script(js)
    time.sleep(1)

#将打开的界面截图保存，方便观察
a=browser.get_screenshot_as_file("E:/WorkSpace/Python/test.jpg")
#获取当前页面所有源码（此时包含触发出来的异步加载的资源）
data=browser.page_source
#将相关网页源码写入本地文件中，方便分析
fh=open("E:/WorkSpace/Python/dongman.html","w",encoding="utf-8")

fh.write(data)
fh.close()

#结束了PhantomJS的使用之后，我们需要关闭一下浏览器，所以，我们在代码后添加如下一行代码
browser.quit()

#我们可以通过正则表达式'
import re
import urllib

#构造正则表达式提取动漫图片资源网址
pat='

#获取所有动漫图片资源网址
allid=re.compile(pat).findall(data)
for i in range(0,len(allid)):
    #得到当前网址
    thisurl=allid[i]
    #去除网址中的多余元素amp;
    thisurl2=thisurl.replace("amp;","")+".jpg"
    #输出当前爬取的网址
    print(thisurl2)
    #设置将动漫存储到本地的本地目录
    localpath="E:/WorkSpace/dongman/"+str(i)+".jpg"
    #通过urllib对动漫图片资源进行爬取
    urllib.request.urlretrieve(thisurl2,filename=localpath)

爬取小说的例子

#coding=utf-8
#BeautifulSoup处理HTML标签包括搜索,遍历相应的标签,但是将HTML文档转化为可读文档,属于浏览器渲染的行为,bs一般是不提供的,具体的解决办法有用正则表达式,用nltk,用js的innnerHTML
#import nltk
#content=nltk.clean_html(contentHTML)  #nltk后来的版本不支持clear_html()和clear_url()
#[s.extract() for s in contentHTML.find_all('p',text="")] #去除了所有的p标签
import requests
from bs4 import BeautifulSoup

#from HTMLParser import HTMLParser  #python2
from html.parser import HTMLParser  #python3
from re import sub  
from sys import stderr  
from traceback import print_exc  
import os

class MyHTMLParser(HTMLParser):  
    def __init__(self):  
        HTMLParser.__init__(self)  
        self.texts=""#存放处理的结果
    def handle_data(self, data):  
        data=data.strip()  #去除首尾空格
        data='  '+data   #段落首部空格
        self.texts+=data

    #处理标签
    #def handle_starttag(self, tag, attrs):  #在遇到开始标签时发生的行为

    #def handle_startendtag(self, tag, attrs):  #在遇到开始或者结束标签时发生的行为

    def handle_endtag(self,tag):  #在遇到结束标签时发生的行为
        if tag == 'p':  
            self.texts+='\n\n'

    def text(self):  
        return self.texts

#解析HTML为Text
def dehtml(text):  
    try:  
        parser = MyHTMLParser()  
        parser.feed(text)  
        parser.close()  
        return parser.text()  
    except:  
        print_exc(file=stderr)  
        return text  

#获取网页源代码
def getHTMLText(url):
    try:
        head={}
        head['User-Agent'] ="Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36"
        r=requests.get(url,headers=head)
        r.raise_for_status()#如果状态不是200,引发HTTPError异常
        r.encoding=r.apparent_encoding
        return r.text   
    except:
        return "获取网页产生异常"

if __name__=="__main__":
    print('starting...')
    bookUrl="http://www.shuhuanghuang.com/book/44674.html"#小说首页
    path="E:/WorkSpace/novel/"#下载小说位置
    soup=BeautifulSoup(getHTMLText(bookUrl),'lxml')
    infoSoup=soup.find('div',class_='info-box')
    bookTitle=infoSoup.find('p',class_='title').text
    bookDescription=infoSoup.get_text()
    bookPath=path+bookTitle;
    if not os.path.exists(bookPath):  #不能用!来取非
        os.makedirs(bookPath) 
    descriptionFile=bookPath+'/'+'Description.txt'
    if not os.path.exists(descriptionFile):
        open(descriptionFile,'w+').close()      
    f=open(descriptionFile,'w')
    f.write(bookDescription)
    f.close()
    print('downloading...')
    chapterUrl=soup.find('a',class_='read',text='阅读')['href'] #小说第一章url
    hasNext=True;
    while(hasNext):
        chapterSoup = BeautifulSoup(getHTMLText(chapterUrl),'lxml')
        title=chapterSoup.find('div',class_='title').string #小说标题
        title=title.replace('\r\n','').replace('\t','')
        contentHTML=chapterSoup.find('div',class_='content')
        contentStr=contentHTML.prettify().replace('\n','').replace('
 
','')
        content=dehtml(contentStr)
        chapterPath=bookPath+'/'+title+'.txt'
        if not os.path.exists(chapterPath):
            open(chapterPath,'w+').close()
        f=open(chapterPath,'w')
        f.write(content)
        f.close()
        print(title+'  has downloaded!')
        nextChapter=chapterSoup.find('a',class_='next')
        if not nextChapter:
            hasNext=False
            break
        chapterUrl=nextChapter['href']
    print('All finished!')