爬虫系列(二十三):阳光热线问政平台

作者: 文子轩 | 来源:发表于2018-01-31 17:16 被阅读30次

    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

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