一.POST请求
class Postspider(scripy.Spider): name = "post" # allowed_domains = ["www.xxx.com"] start_urls = ["https.//fanyi.baidu.com/sug"] def start_requests(self): data = { "kw": "dog" } for url in self.start_urls: yield scrapy.FormRequest(url=url, formdata=data, calback=self.parse) def parse(self, response): print(response.text)
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。
ex: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。
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
items.py:
-*- 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()
管道文件:
# -*- 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()
三、log日志相关
- 在使用scrapy crawl spiderFileName运行程序时,在终端里打印输出的就是scrapy的日志信息。
- 日志信息的种类:
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
- 设置日志信息指定输出:
在settings.py配置文件中,加入LOG_LEVEL = ‘指定日志信息种类’即可。LOG_FILE = ‘log.txt‘则表示将日志信息写入到指定文件中进行存储。
原文地址:https://www.cnblogs.com/qq631243523/p/10471699.html
时间: 2024-11-05 01:02:06