5.2. (scrapy案例二)阳光热线问政平台爬虫

阳光热线问政平台

http://wz.sun0769.com/index.php/question/questionType?type=4

爬取投诉帖子的编号、帖子的url、帖子的标题，和帖子里的内容。

items.py

import scrapy

class DongguanItem(scrapy.Item):
    # 每个帖子的标题
    title = scrapy.Field()
    # 每个帖子的编号
    number = scrapy.Field()
    # 每个帖子的文字内容
    content = scrapy.Field()
    # 每个帖子的url
    url = scrapy.Field()

spiders/sunwz.py

Spider 版本

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

import scrapy
from dongguan.items import DongguanItem

class SunSpider(CrawlSpider):
    name = 'sun'
    allowed_domains = ['wz.sun0769.com']
    url = 'http://wz.sun0769.com/index.php/question/questionType?type=4&page='
    offset = 0
    start_urls = [url + str(offset)]

    def parse(self, response):
        # 取出每个页面里帖子链接列表
        links = response.xpath("//div[@class='greyframe']/table//td/a[@class='news14']/@href").extract()
        # 迭代发送每个帖子的请求，调用parse_item方法处理
        for link in links:
            yield scrapy.Request(link, callback = self.parse_item)
        # 设置页码终止条件，并且每次发送新的页面请求调用parse方法处理
        if self.offset <= 71130:
            self.offset += 30
            yield scrapy.Request(self.url + str(self.offset), callback = self.parse)

    # 处理每个帖子里
    def parse_item(self, response):
        item = DongguanItem()
        # 标题
        item['title'] = response.xpath('//div[contains(@class, "pagecenter p3")]//strong/text()').extract()[0]

        # 编号
        item['number'] = item['title'].split(' ')[-1].split(":")[-1]

        # 文字内容，默认先取出有图片情况下的文字内容列表
        content = response.xpath('//div[@class="contentext"]/text()').extract()
        # 如果没有内容，则取出没有图片情况下的文字内容列表
        if len(content) == 0:
            content = response.xpath('//div[@class="c1 text14_2"]/text()').extract()
            # content为列表，通过join方法拼接为字符串，并去除首尾空格
            item['content'] = "".join(content).strip()
        else:
            item['content'] = "".join(content).strip()

        # 链接
        item['url'] = response.url

        yield item

CrawlSpider 版本

# -*- coding: utf-8 -*-
import scrapy
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule
from dongguan.items import DongguanItem
import time


class SunSpider(CrawlSpider):
    name = 'sun'
    allowed_domains = ['wz.sun0769.com']
    start_urls = ['http://wz.sun0769.com/index.php/question/questionType?type=4&page=']

    # 每一页的匹配规则
    pagelink = LinkExtractor(allow=('type=4'))
    # 每个帖子的匹配规则
    contentlink = LinkExtractor(allow=r'/html/question/\d+/\d+.shtml')

    rules = [
        # 本案例为特殊情况，需要调用deal_links方法处理每个页面里的链接
        Rule(pagelink, process_links = "deal_links", follow = True),
        Rule(contentlink, callback = 'parse_item')
    ]

    # 需要重新处理每个页面里的链接，将链接里的‘Type&type=4?page=xxx’替换为‘Type?type=4&page=xxx’（或者是Type&page=xxx?type=4’替换为‘Type?page=xxx&type=4’），否则无法发送这个链接
    def deal_links(self, links):
        for link in links:
            link.url = link.url.replace("?","&").replace("Type&", "Type?")
            print link.url
        return links


    def parse_item(self, response):
        print response.url
        item = DongguanItem()
        # 标题
        item['title'] = response.xpath('//div[contains(@class, "pagecenter p3")]//strong/text()').extract()[0]

        # 编号
        item['number'] = item['title'].split(' ')[-1].split(":")[-1]

        # 文字内容，默认先取出有图片情况下的文字内容列表
        content = response.xpath('//div[@class="contentext"]/text()').extract()
        # 如果没有内容，则取出没有图片情况下的文字内容列表
        if len(content) == 0:
            content = response.xpath('//div[@class="c1 text14_2"]/text()').extract()
            # content为列表，通过join方法拼接为字符串，并去除首尾空格
            item['content'] = "".join(content).strip()
        else:
            item['content'] = "".join(content).strip()

        # 链接
        item['url'] = response.url

        yield item

pipelines.py

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

# 文件处理类库，可以指定编码格式
import codecs
import json

class JsonWriterPipeline(object):

    def __init__(self):
        # 创建一个只写文件，指定文本编码格式为utf-8
        self.filename = codecs.open('sunwz.json', 'w', encoding='utf-8')

    def process_item(self, item, spider):
        content = json.dumps(dict(item), ensure_ascii=False) + "\n"
        self.filename.write(content)
        return item

    def spider_closed(self, spider):
        self.file.close()

settings.py

ITEM_PIPELINES = {
   
    'dongguan.pipelines.DongguanPipeline': 300,
}

# 日志文件名和处理等级
LOG_FILE = "dg.log"
LOG_LEVEL = "DEBUG"

在项目根目录下新建main.py文件,用于调试

from scrapy import cmdline
cmdline.execute('scrapy crawl sunwz'.split())

执行程序

py2 main.py