scrapy (三) : 请求传参

scrapy 请求传参

1.定义数据结构item.py文件

'''
field: item.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 MovieprojectItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    # 电影海报
    # 一级页面要抓取的内容
    post = scrapy.Field()
    name = scrapy.Field()
    _type = scrapy.Field()

    # 二级页面要抓取的内容
    director = scrapy.Field()
    design = scrapy.Field()
    actor = scrapy.Field()
    info = scrapy.Field()

2.爬虫文件

# -*- coding: utf-8 -*-
# -*- coding: utf-8 -*-
import scrapy
from movieproject.items import MovieprojectItem

class MovieSpider(scrapy.Spider):
    name = 'movie'
    allowed_domains = ['www.id97.com']
    start_urls = ['http://www.id97.com/movie/']
    url = 'http://www.id97.com/movie/?page={}'
    page = 1

    '''
    (1)只需要提取页码链接，只提取第一页的信息即可
    (2)需要写两个规则，一个规则提取详情页面，一个规则是提取页码链接
    '''

    def parse(self, response):
        # 先查找所有的movie_div
        movie_div_list = response.xpath('//div[starts-with(@class,"col-xs-1-5")]')
        # 遍历所有的div，去获取每一个详细的信息
        for odiv in movie_div_list:
            item = MovieprojectItem()
            # 获取电影海报
            item['post'] = odiv.xpath(".//img/@data-original").extract_first()

            # 获取电影名字
            item['name'] = odiv.xpath("./div/div/h1/a/text()").extract_first()
            # 获取电影类型
            item['_type'] = odiv.xpath("./div/div/div/a/text()").extract()

            # 获取详情页面
            detail_href = odiv.xpath('./div/a/@href').extract_first()
						'''
						向详情页面发送请求
            将item向二级传递过去，到二级页面接受并且接着提取其他的信息
            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
						'''

            yield scrapy.Request(url=detail_href,callback=self.parse_detail, meta={'item': item})
# 爬取其他页面
        if self.page <= 5:
            self.page += 1
            url = self.url.format(self.page)
            print(url)
            yield scrapy.Request(url=url, callback=self.parse)

    def parse_detail(self,response):
        # 首先获取到上一级传递过来的item
        item = response.meta['item']
        # 在这个页面中接着提取电影的其它信息即可
        # 获取导演
        item['director'] = response.xpath("//div[starts-with(@class,'col-xs-8')]/table/tbody/tr/td[2]/a/text()").extract()
        # 获取编剧
        item['design'] = response.xpath("//div[starts-with(@class,'col-xs-8')]/table/tbody/tr[2]/td[2]/a/text()").extract()
        # 获取主演
        item['actor'] = response.xpath("//div[starts-with(@class,'col-xs-8')]/table/tbody/tr[3]/td[2]/a/text()").extract()
        # 获取电影介绍
        item['info'] = response.xpath("//div[@class='col-xs-12 movie-introduce']/p/text()").extract_first()

        #提交item到管道
        yield item

3.管道文件

# -*- coding: utf-8 -*-
'''
filed: pipelines.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
from scrapy.utils.project import get_project_settings
import pymysql

class MovieprojectPipeline(object):
    def open_spider(self,spider):
        self.fp = open("movie.json","w",encoding="utf8")
    def process_item(self, item, spider):
        obj = dict(item)
        string = json.dumps(obj,ensure_ascii=False)
        self.fp.write(string+'\n')
        # print("写入成功")
        return item
    def close_spider(self,spider):
        self.fp.close()

class MovieMysqlPipeline(object):
    def open_spider(self,spider):
        # 获取所有的配置信息
        settings = get_project_settings()
        # 链接数据库
        host = settings['DB_HOST']
        port = settings['DB_PORT']
        user = settings['DB_USER']
        pwd = settings['DB_PWD']
        name = settings['DB_NAME']
        charset = settings['DB_CHARSET']

        self.conn = pymysql.connect(host=host, port=port, user=user, password=pwd, db=name, charset=charset)

    def process_item(self, item, spider):
        # 拼接sql语句
        sql = 'insert into movie(post, name, type, director, design, actor, info) values("%s","%s","%s","%s","%s","%s","%s")' % (item['post'], item['name'], item['_type'], item['director'], item['design'], item['actor'], item['info'])

        # 获取游标
        cursor = self.conn.cursor()

        # 执行sql语句
        try:
            cursor.execute(sql)
            self.conn.commit()
        except Exception as e:
            self.conn.rollback()
        return item

    def close_spider(self,spider):
        # 关闭数据库
        self.conn.close()