Scrapy:python3下的第一次运行测试

原创
2016/06/17 09:52
阅读数 485

####1,引言

Scrapy的架构初探》一文讲解了Scrapy的架构,本文就实际来安装运行一下Scrapy爬虫。本文以官网的tutorial作为例子,完整的代码可以在github上下载。

####2,运行环境配置

  • 本次测试的环境是:Windows10,Python3.4.3 32bit
  • 安装Scrapy:$ pip install Scrapy                 #实际安装时,由于服务器状态的不稳定,出现好几次中途退出的情况

####3,编写运行第一个Scrapy爬虫

3.1. 生成一个新项目:tutorial

$ scrapy startproject tutorial

项目目录结构如下:  

3.2.  定义要抓取的item # -- coding: utf-8 --

# Define here the models for your scraped items
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/items.html

import scrapy

class DmozItem(scrapy.Item):
    title = scrapy.Field()
    link = scrapy.Field()
    desc = scrapy.Field()

3.3. 定义Spider

import scrapy
from tutorial.items import DmozItem

class DmozSpider(scrapy.Spider):
    name = "dmoz"

    allowed_domains = ["dmoz.org"]     start_urls = [         "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",         "http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/"     ]

    def parse(self, response):

        for sel in response.xpath('//ul/li'):              item = DmozItem()             item['title'] = sel.xpath('a/text()').extract()             item['link'] = sel.xpath('a/@href').extract()             item['desc'] = sel.xpath('text()').extract()             yield item

3.4. 运行

$ scrapy crawl dmoz -o item.json
  1. 结果报错:     A) ImportError: cannot import name '_win32stdio'    B) ImportError: No module named 'win32api'

  2. 查错过程: 查看官方的FAQstackoverflow上的信息,原来是scrapy在python3上测试还不充分,还有小问题。

  3. 解决过程:    A)需要手工去下载twisted/internet下的_win32stdio和_pollingfile,存放到python目录的lib\sitepackages\twisted\internet下    B)下载并安装pywin32

再次运行,成功!在控制台上可以看到scrapy的输出信息,待运行完成退出后,到项目目录打开结果文件items.json, 可以看到里面以json格式存储的爬取结果

[
{"title": ["        About       "], "desc": [" ", " "], "link": ["/docs/en/about.html"]},
{"title": ["   Become an Editor "], "desc": [" ", " "], "link": ["/docs/en/help/become.html"]},
{"title": ["            Suggest a Site          "], "desc": [" ", " "], "link": ["/docs/en/add.html"]},
{"title": [" Help             "], "desc": [" ", " "], "link": ["/docs/en/help/helpmain.html"]},
{"title": [" Login                       "], "desc": [" ", " "], "link": ["/editors/"]},
{"title": [], "desc": [" ", " Share via Facebook "], "link": []},
{"title": [], "desc": [" ", "  Share via Twitter  "], "link": []},
{"title": [], "desc": [" ", " Share via LinkedIn "], "link": []},
{"title": [], "desc": [" ", " Share via e-Mail   "], "link": []},
{"title": [], "desc": [" ", " "], "link": []},
{"title": [], "desc": [" ", "  "], "link": []},
{"title": ["        About       "], "desc": [" ", " "], "link": ["/docs/en/about.html"]},
{"title": ["   Become an Editor "], "desc": [" ", " "], "link": ["/docs/en/help/become.html"]},
{"title": ["            Suggest a Site          "], "desc": [" ", " "], "link": ["/docs/en/add.html"]},
{"title": [" Help             "], "desc": [" ", " "], "link": ["/docs/en/help/helpmain.html"]},
{"title": [" Login                       "], "desc": [" ", " "], "link": ["/editors/"]},
{"title": [], "desc": [" ", " Share via Facebook "], "link": []},
{"title": [], "desc": [" ", "  Share via Twitter  "], "link": []},
{"title": [], "desc": [" ", " Share via LinkedIn "], "link": []},
{"title": [], "desc": [" ", " Share via e-Mail   "], "link": []},
{"title": [], "desc": [" ", " "], "link": []},
{"title": [], "desc": [" ", "  "], "link": []}
]

第一次运行scrapy的测试成功

####4,接下来的工作

接下来,我们将使用GooSeeker API来实现网络爬虫,省掉对每个item人工去生成和测试xpath的工作量。

目前有2个计划:

  1. 在gsExtractor中封装一个方法:从xslt内容中自动提取每个item的xpath
  2. 从gsExtractor的提取结果中自动提取每个item的结果

具体选择哪个方案,将在接下来的实验中确定,并发布到gsExtractor新版本中

####5,文档修改历史

2016-06-17:V1.0,首次发布

展开阅读全文
加载中
点击引领话题📣 发布并加入讨论🔥
打赏
0 评论
0 收藏
0
分享
返回顶部
顶部