关于scrapy的一些练习

练习代码如下：

主函数：

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

import scrapy
from scrapy.selector import Selector
from lxml import etree
from ScrapyTest.items import ScrapytestItem

class testSpider(scrapy.Spider):
    #爬虫名字
    name = "itcast"
    #允许爬取的域名
    # allowwd_domains = ["http://www.itcast.cn/"]
    #爬取信息的网址
    start_urls = (
        "http://www.hs-bianma.com/search.php?ser=%E5%8F%A3%E7%BA%A2&ai=1",
    )

    def parse(self, response):
        # print(response.body)
        #先爬取口红列表中的所有信息
        items = response.xpath("/html/body/div[2]/div")
        print(items)
        #使用xpath，在items的基础上继续查找口红的具体信息
        #使用replace（）方法删除多余的字段
        #使用yield将爬取信息传给items.py
        for item in items:
            str = './/div[1]/text()'
            m = item.xpath(str).extract_first()
            n = item.xpath('.//div[2]').extract_first()
            # a = response.xpath('/html/body/div[2]/div/div[2]').extract()[11]
            b = item.xpath(".//div[3]/a[1]/@href").extract_first()
            c = item.xpath(".//div[3]/a[2]/@href").extract_first()
            a1 = n.replace('</div>', '').replace('<div>', '').replace('<span class="red">', '').replace('</span>', '')
            a1 = a1.replace('<b>商品描述</b>', '')
            # print(m)
            # print(a1)
            # print(b)
            # print(c)
            # print(a1)
            item = ScrapytestItem()
            item['hscode'] = m
            item['商品描述'] = a1
            item['归类实例'] = b
            item['详情'] = c
            yield item

        # for m in mlist:
        #     test_list = {}
        #     print(test_list)
        #
            # test_list['m'] = m
            # print(m)
        #判断下一页是否存在，存在着交给newParse处理
        next_page = response.xpath("//*[@id='main']/div/div[3]/a[1]/@href").extract_first()
        next_page = 'http://www.hs-bianma.com'+next_page
        print(next_page)
        if next_page is not None:
            next_page = response.urljoin(next_page)
            yield scrapy.Request(next_page, callback=self.myParse)

    def myParse(self, response):
        # print(response.text)
        second_items = response.xpath(".//*[@id='main']/div")
        # print(second_items)
        for second_item in second_items:
            second_hscode = second_item.xpath(".//div[1]").extract_first()
            second_hscode = second_hscode.replace('<span class="red">', '').replace('</span>', '')
            second_hscode = second_hscode.replace('<div>', '').replace('</div>','').replace('<b>hscode</b>','')
            second_description = second_item.xpath(".//div[2]/text()").extract_first()
            second_details = second_item.xpath(".//div[3]/a/@href").extract_first()
            print(second_hscode)
            print(second_description)
            print(second_details)
            item = ScrapytestItem()
            item['second_hscode'] = second_hscode
            item['二级商业描述'] = second_description
            item['二级详情'] = second_details
            yield item

setting.py:

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

# Scrapy settings for ScrapyTest project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://doc.scrapy.org/en/latest/topics/settings.html
#     https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://doc.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'ScrapyTest'

SPIDER_MODULES = ['ScrapyTest.spiders']
NEWSPIDER_MODULE = 'ScrapyTest.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#伪装为火狐浏览器访问
USER_AGENT = 'Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0'

# 修改编码为gbk，utf-8不行
FEED_EXPORT_ENCODING = 'gbk'
#输出csv文件
FEED_URI = u'file:///F://douban.csv'
FEED_FORMAT = 'CSV'


# Obey robots.txt rules
ROBOTSTXT_OBEY = False

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 ScrapytestItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()

    hscode = scrapy.Field()
    商品描述 = scrapy.Field()
    归类实例 = scrapy.Field()
    详情 = scrapy.Field()

    second_hscode = scrapy.Field()
    二级商业描述 = scrapy.Field()
    二级详情 = scrapy.Field()
    pass

start.py:

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


class ScrapytestPipeline(object):
    def process_item(self, item, spider):
        return item

class FilePipeLine(object):
    def __init__(self):
        self.file = open('f:/hjd', 'wb')

    #输出txt文件
    def process_item(self, item, spider):
        line = "%s\t%s\t%s\t%s\t%s\t%s\n" % (item['hscode'],
                                             item['description'],
                                             item['example'],
                                             item['details'])
        self.file.write(line.encode("utf-8"))
        return item