2:url有规律的多页面爬取

举例网站：http://www.luoo.net/music/期刊号

e.g:http://www.luoo.net/music/760

打算爬取其title：Hello World；pic；desc：本期音乐为......《8-bit Love》。

步骤：

1）：建立项目

　　在shell中你对应的目录下：scrapy startproject luoo

　　在pycharm中打开luoo文件夹

2)：编写items.py

import scrapy
class LuooItem(scrapy.Item):
    url = scrapy.Field()
    title = scrapy.Field()
    pic = scrapy.Field()
    desc = scrapy.Field()

3)：编写spider
　　在spiders文件夹下建立luoospider.py

　　

import scrapy
from luoo.items import LuooItem

class LuooSpider(scrapy.Spider):
    name = "luoo"
    allowed_domains = ["luoo.net"]
    start_urls = []
    for i in range(750,763):
        url = 'http://www.luoo.net/music/%s'%(str(i))
        start_urls.append(url)

    def parse(self, response):
        item = LuooItem()
        item['url'] = response.url
        item['title'] = response.xpath('//span[@class="vol-title"]/text()').extract()
        item['pic'] = response.xpath('//img[@class="vol-cover"]/@src').extract()
        item['desc'] = response.xpath('//div[@class="vol-desc"]/text()').extract()
        return item

4)pipelines.py不动
5）在command中进入luoo目录
　　scrapy list   列出可用的爬虫（luoo）
　　scrapy crawl luoo -o result.csv(执行爬虫并且以result.csv保存到当前目录下)
6）用notepad++打开result.py并且更改格式为ANSI后保存，再用excel打开就不会有乱码了

*遗留to do：
1）数据考虑后期迁移到mysql数据库
2）单独把图片保存到图片格式的文件夹中


memory：顺便附上两个月前用urllib库实现的此功能代码（python3.4）
　　　　 现在看看用scrapy真的是方便太多了，更别提其牛逼呼呼的可扩展性：

import urllib.request
import re
import time

def openurl(urls):   
    htmls=[]
    for url in urls:
        req=urllib.request.Request(url)
        req.add_header('User-Agent','Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36')    
  #      Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0
        response = urllib.request.urlopen(url)
        htmls.append(response.read())
        time.sleep(5)
    return htmls

def jiexi(htmls):
    pics=[]
    titles=[]
    contents=[]
    for html in htmls:
        html = html.decode('utf-8')
        pics.append(re.findall('<div class="player-wrapper".*?>.*?<img.*?src="(.*?).jp.*?".*?alt=".*"',html,re.S))
        titles.append(re.findall('class="vol-title">(.*?)</span>',html,re.S))
        contents.append(re.findall('<div.*?class="vol-desc">.*?(.*?)</div>',html,re.S))
        
    i = len(titles)
    with open('C:\Users\Administrator\Desktop\test.txt', 'w') as f:
        for x in range(i):
            print("正在下载期刊：%d" %(746-x))
            f.write("期刊名："+str(titles[x])[2:-2]+"
")
            f.write("图片链接："+str(pics[x])[2:-2]+".jpg
")
            content = str(contents[x])[4:-2]
            content.strip()
            print(content.count("""<br>
""")) 
            content.replace("""<br>
""","#")
            f.write("配诗："+content+"


")


yur='http://www.luoo.net/music/'
urls = []
for i in range(657,659):
    urls.append(yur + str(i))

htmls = openurl(urls)
pics = jiexi(htmls)