• 日志等级与请求传参


    日志等级:
    ERROR : 一般错误

            WARNING : 警告

            INFO : 一般的信息

            DEBUG : 调试信息

            默认的显示级别是DEBUG

    可以在配置文件中settings中进行日志信息的指定输出:
    #指定日志信息的输出
    #LOG_LEVEL = 'DEBUG'

    #将日志信息写入到文件中进行存储
    LOG_FILE = 'log.txt'


    二.请求传参

      - 在某些情况下,我们爬取的数据不在同一个页面中,例如,我们爬取一个电影网站,电影的名称,评分在一级页面,而要爬取的其他电影详情在其二级子页面中。这时我们就需要用到请求传参。

      - 案例展示:爬取www.id97.com电影网,将一级页面中的电影名称,类型,评分一级二级页面中的上映时间,导演,片长进行爬取。

    # -*- coding: utf-8 -*-
    import scrapy
    from moviePro.items import MovieproItem
    
    class MovieSpider(scrapy.Spider):
        name = 'movie'
        allowed_domains = ['www.id97.com']
        start_urls = ['http://www.id97.com/']
    
        def parse(self, response):
            div_list = response.xpath('//div[@class="col-xs-1-5 movie-item"]')
    
            for div in div_list:
                item = MovieproItem()
                item['name'] = div.xpath('.//h1/a/text()').extract_first()
                item['score'] = div.xpath('.//h1/em/text()').extract_first()
                #xpath(string(.))表示提取当前节点下所有子节点中的数据值(.)表示当前节点
                item['kind'] = div.xpath('.//div[@class="otherinfo"]').xpath('string(.)').extract_first()
                item['detail_url'] = div.xpath('./div/a/@href').extract_first()
                #请求二级详情页面,解析二级页面中的相应内容,通过meta参数进行Request的数据传递
                yield scrapy.Request(url=item['detail_url'],callback=self.parse_detail,meta={'item':item})
    
        def parse_detail(self,response):
            #通过response获取item
            item = response.meta['item']
            item['actor'] = response.xpath('//div[@class="row"]//table/tr[1]/a/text()').extract_first()
            item['time'] = response.xpath('//div[@class="row"]//table/tr[7]/td[2]/text()').extract_first()
            item['long'] = response.xpath('//div[@class="row"]//table/tr[8]/td[2]/text()').extract_first()
            #提交item到管道
            yield item
    爬虫文件
    # -*- coding: utf-8 -*-
    
    # Define here the models for your scraped items
    #
    # See documentation in:
    # https://doc.scrapy.org/en/latest/topics/items.html
    
    import scrapy
    
    
    class MovieproItem(scrapy.Item):
        # define the fields for your item here like:
        name = scrapy.Field()
        score = scrapy.Field()
        time = scrapy.Field()
        long = scrapy.Field()
        actor = scrapy.Field()
        kind = scrapy.Field()
        detail_url = scrapy.Field()
    items.py
    # -*- coding: utf-8 -*-
    
    # Define your item pipelines here
    #
    # Don't forget to add your pipeline to the ITEM_PIPELINES setting
    # See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
    
    import json
    class MovieproPipeline(object):
        def __init__(self):
            self.fp = open('data.txt','w')
        def process_item(self, item, spider):
            dic = dict(item)
            print(dic)
            json.dump(dic,self.fp,ensure_ascii=False)
            return item
        def close_spider(self,spider):
            self.fp.close()
    管道文件
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  • 原文地址:https://www.cnblogs.com/xujinjin18/p/9747109.html
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