scrapy | 易学教程

Terminate Scrapy if a condition is met

阅读更多关于 Terminate Scrapy if a condition is met

问题 I have written a scraper using scrapy in python. It contains 100 start_urls. I want to terminate the scraping process once a condition is met. ie terminate scraping of a particular div is found. By terminate I mean it should stop scraping all the urls . Is it possible 回答1: What you're looking for is the CloseSpider exception. Add the following line somewhere at the top of your source file: from scrapy.exceptions import CloseSpider And when you detect that your termination condition is met,

scrapy入门案例

阅读更多关于 scrapy入门案例

一. 新建项目(scrapy startproject) 在开始爬取之前，必须创建一个新的Scrapy项目。进入自定义的项目目录中，运行下列命令： scrapy startproject scrapyDemo 其中， mySpider 为项目名称，可以看到将会创建一个 scrapyDemo 文件夹，目录结构大致如下：各个主要文件的作用： scrapy.cfg ：项目的配置文件 scrapyDemo / ：项目的Python模块，将会从这里引用代码 scrapyDemo /items.py ：项目的目标文件 scrapyDemo /pipelines.py ：项目的管道文件 scrapyDemo /settings.py ：项目的设置文件 scrapyDemo /spiders/ ：存储爬虫代码目录抓取：https://www.cnblogs.com/loaderman/ 网站里的所有讲师的标题、描述、详情链接地址和日期。打开 scrapyDemo 目录下的items.py Item 定义结构化数据字段，用来保存爬取到的数据，有点像Python中的dict，但是提供了一些额外的保护减少错误。可以通过创建一个 scrapy.Item 类，并且定义类型为 scrapy.Field的类属性来定义一个Item（可以理解成类似于ORM的映射关系）。接下来

Scrapy部署到Scrapyd服务器

阅读更多关于 Scrapy部署到Scrapyd服务器

1.环境搭配 1.1安装scrapyd pip install scrapyd Scrapyd是一个服务，用来运行scrapy爬虫的它允许你部署你的scrapy项目以及通过HTTP JSON的方式控制你的爬虫官方文档： http://scrapyd.readthedocs.org/ DOS 成功样例可视化成功样例输入 url: http://127.0.0.1:6800/ 1.2安装Scrapy-client pip install scrapy-client scrapy-client 相当于一个客户端它允许我们将本地的scrapy项目打包发送到scrapyd 这个服务端 2.部署部署Scrapyd 首先进入Scrapy框架的根目录，里面有一个 scrapy.cfg 文件本scrapy项目叫 demo 修改 scrapy.cfg 文件首先将url的注释去除，url，就是我们要将scrapy部署到的服务器地址随后将 [deploy] 改为 [deploy:scrapyd1] ，这里需要注意的是scrapyd1是我们自己定义的，任意均可。进入 D:\ProgramData\Anaconda3\Scripts （python安装的地址）在此目录下创建文件 scrapyd-deploy.bat 文件的内容为（内容中的 D:\ProgramData\Anaconda3

scrapy-redis 分布式爬虫

阅读更多关于 scrapy-redis 分布式爬虫

一、介绍原来scrapy的Scheduler维护的是本机的任务队列（存放Request对象及其回调函数等信息）+本机的去重队列（存放访问过的url地址）所以实现分布式爬取的关键就是，找一台专门的主机上运行一个共享的队列比如Redis，然后重写Scrapy的Scheduler，让新的Scheduler到共享队列存取Request，并且去除重复的Request请求，所以总结下来，实现分布式的关键就是三点： #1、共享队列 #2、重写Scheduler，让其无论是去重还是任务都去访问共享队列 #3、为Scheduler定制去重规则（利用redis的集合类型） #安装： pip3 install scrapy-redis #源码： D:\python3.6\Lib\site-packages\scrapy_redis 二、scrapy-redis组件（settings配置过滤和调度） 1、只使用scrapy-redis的去重功能源码分析 #一、源码：D:\python3.6\Lib\site-packages\scrapy_redis\dupefilter.py #二、配置scrapy使用redis提供的共享去重队列 #2.1 在settings.py中配置链接Redis REDIS_HOST = 'localhost' # 主机名 REDIS_PORT = 6379 # 端口

Multi POST query (session mode)

阅读更多关于 Multi POST query (session mode)

问题 I am trying to interrogate this site to get the list of offers. The problem is that we need to fill 2 forms (2 POST queries) before receiving the final result. This what I have done so far: First I am sending the first POST after setting the cookies: library(httr) set_cookies(.cookies = c(a = "1", b = "2")) first_url <- "https://compare.switchon.vic.gov.au/submit" body <- list(energy_category="electricity", location="home", "location-home"="shift", "retailer-company"="", postcode="3000",

爬虫框架 Scrapy

阅读更多关于爬虫框架 Scrapy

一介绍 crapy一个开源和协作的框架，其最初是为了页面抓取 (更确切来说, 网络抓取 )所设计的，使用它可以以快速、简单、可扩展的方式从网站中提取所需的数据。但目前Scrapy的用途十分广泛，可用于如数据挖掘、监测和自动化测试等领域，也可以应用在获取API所返回的数据(例如 Amazon Associates Web Services ) 或者通用的网络爬虫。 Scrapy 是基于twisted框架开发而来，twisted是一个流行的事件驱动的python网络框架。因此Scrapy使用了一种非阻塞（又名异步）的代码来实现并发。整体架构大致如下 The data flow in Scrapy is controlled by the execution engine, and goes like this: The Engine gets the initial Requests to crawl from the Spider . The Engine schedules the Requests in the Scheduler and asks for the next Requests to crawl. The Scheduler returns the next Requests to the Engine . The Engine sends the

ImportError : cannot import name '_win32stdio'

阅读更多关于 ImportError : cannot import name '_win32stdio'

问题 I am working with Scrapy framework to scrap out data from website, but getting the following error in command prompt: ImportError: cannot import name '_win32stdio' Traceback is attached as a screenshot. Kindly revert if require directory structure of my program's directory. 回答1: Scrapy can work with Python 3 on windows if you make some minor adjustments: Copy the _win32stdio and _pollingfile to the appropriate directory under site-packages. Namely, twisted-dir\internet. Download these from

Logging to specific error log file in scrapy

阅读更多关于 Logging to specific error log file in scrapy

问题 I am running a log of scrapy by doing this: from scrapy import log class MySpider(BaseSpider): name = "myspider" def __init__(self, name=None, **kwargs): LOG_FILE = "logs/spider.log" log.log.defaultObserver = log.log.DefaultObserver() log.log.defaultObserver.start() log.started = False log.start(LOG_FILE, loglevel=log.INFO) super(MySpider, self).__init__(name, **kwargs) def parse(self,response): .... raise Exception("Something went wrong!") log.msg('Something went wrong!', log.ERROR) #

Newbie: How to overcome Javascript “onclick” button to scrape web page?

阅读更多关于 Newbie: How to overcome Javascript “onclick” button to scrape web page?

问题 This is the link I want to scrape: http://www.prudential.com.hk/PruServlet?module=fund&purpose=searchHistFund&fundCd=MMFU_U The "English Version" tab is at the upper right hand corner in order to show the English version of the web page. There is a button I have to press in order to read the funds information on the web page. If not, the view is blocked, and using scrapy shell always result empty []. <div onclick="AgreeClick()" style="width:200px; padding:8px; border:1px black solid;

Scrapy : storing the data

阅读更多关于 Scrapy : storing the data

问题 I'm new with python and scrapy. I'm tring to follow the Scrapy tutorial but I don't understand the logic of the storage step. scrapy crawl spidername -o items.json -t json scrapy crawl spidername --set FEED_URI=output.csv --set FEED_FORMAT=csv I dont understand the signification of : -o -t --set Thank you for your help 回答1: You can view a list of available commands by typing scrapy crawl -h from within your project directory. scrapy crawl spidername -o items.json -t json -o specifies the

订阅 scrapy