[Scrapy]爬取糗事百科段子

1.Python爬虫实战一之爬取糗事百科段子
（http://cuiqingcai.com/990.html）
2.在工作目录创建myproject

scrapy startproject myproject

3.编写/myproject/myproject/items.py

# -*- coding: utf-8 -*-

# Define here the models for your scraped items
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/items.html

import scrapy

#Item是需要的数据进行格式化，方便后期处理
class MyItem(scrapy.Item):
    user = scrapy.Field()
    content = scrapy.Field()
    godComment = scrapy.Field()

4.编写/myproject/myproject/spiders/MySpider.py

# -*- coding:utf-8 -*-
import scrapy
import re

from myproject.items import MyItem

#Spider是指定URL，发送请求和接收原始数据，再根据Item进行数据操作
class MySpider(scrapy.Spider):
    name = 'myspider'

    #可传入pageIndex参数合成完整URL
    def __init__(self, pageIndex=None, *args, **kwargs):
        super(MySpider, self).__init__(*args, **kwargs)
        self.start_urls = ['http://www.qiushibaike.com/hot/page/%s' % pageIndex]

    #根据Item进行数据操作
    def parse(self, response):
        #print response.body.decode('response.encoding') #打印原始数据
        pattern = re.compile('
.*?
(.*?)
' + 
                        '.*?' + 
                        '
.*?(.*?).*?
' +
                         '.*?' + 
                        '
(.*?)
'
                        ,re.S)
        items = re.findall(pattern,response.body.decode(response.encoding))
        print ("lin len: %d"%(len(items)))
        for item in items:         
            print ("lin User: %s"%(item[0].strip()))
            print ("lin Content: %s"%(item[1].strip()))
            print ("lin God comments: %s"%(item[2].strip()))
            myItems = MyItem(user=item[0], content=item[1], godComment=item[2])
            yield myItems

5.设置/myproject/myproject/settings.py的headers

DEFAULT_REQUEST_HEADERS = {
  'User-Agent' : 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
}

6.执行myspider，传入pageIndex=1，结果数据保存为items.json

scrapy crawl myspider -a pageIndex=1 -o items.json

7.结果输出和items.json出现Export Unicode字符集问题

8.Scrapy中关于Export Unicode字符集问题解决
（http://blog.csdn.net/peihaozhu/article/details/53022236）
8.1设置/myproject/myproject/settings.py

from scrapy.exporters import JsonLinesItemExporter  
class CustomJsonLinesItemExporter(JsonLinesItemExporter):  
    def __init__(self, file, **kwargs):  
        super(CustomJsonLinesItemExporter, self).__init__(file, ensure_ascii=False, **kwargs)

#这里只需要将超类的ensure_ascii属性设置为False即可
#同时要在setting文件中启用新的Exporter类

FEED_EXPORTERS = {  
    'json': 'myproject.settings.CustomJsonLinesItemExporter',  
}  

8.2再次执行，解决items.json出现Export Unicode字符集的问题，items.json路径为\myproject