scrapy

Scrapy爬虫框架的解析与实例（中国大学MOOC）

由 醉酒当歌 提交于 2021-01-25 13:20:00
Scrapy框架  Scrapy是一个为了爬取网站数据，提取结构性数据而编写的应用框架。 可以应用在包括数据挖掘，信息处理或存储历史数据等一系列的程序中。其最初是为了 页面抓取 (更确切来说, 网络抓取 )所设计的， 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用途广泛，可以用于数据挖掘、监测和自动化测试。  Scrapy 使用了 Twisted 异步网络库来处理网络通讯。整体架构大致如下： 组件 Scrapy Engine 引擎负责控制数据流在系统中所有组件中流动，并在相应动作发生时触发事件。 详细内容查看下面的数据流(Data Flow)部分。 Scheduler(调度器) 调度器从引擎接受request并将他们入队，以便之后引擎请求他们时提供给引擎。 Spiders Spider是Scrapy用户编写用于分析response并提取item(即获取到的item)或额外跟进的URL的类。 每个spider负责处理一个特定(或一些)网站。 Item Pipeline Item Pipeline负责处理被spider提取出来的item。典型的处理有清理、 验证及持久化(例如存取到数据库中)。 下载器中间件(Downloader middlewares)

<scrapy爬虫>scrapy命令行操作

由 人盡茶涼 提交于 2021-01-25 08:38:35
1.mysql数据库 2.mongoDB数据库 3.redis数据库 1.创建项目 scrapy startproject myproject cd myproject 2.创建爬虫 scrapy genspider myspider www.baidu.com scrapy genspider -t crawl myspider www.baidu.com----创建有rules配置 3.运行爬虫 scrapy crawl myspider 4.错误检查 scrapy check ----检查爬虫的语法错误 5.列出爬虫 scrapy list --返回项目里spider名称 6.测试网页 scrapy fetch www.baidu.com scrapy fetch --nolog www.baidu.com ----不会生成日志 scrapy fetch --nolog --headers www.baidu.com --输出headers scrapy fetch --nolog --no-redirect---不会重定向 7.请求网页 把网页源代码保存成文件,在用浏览器打开(调试工具) scrapy view http://www.baidu.com 8.命令行交互模式shell scrapy shell http://www.baidu.com request--

Scrapy - Set TCP Connect Timeout

由 若如初见. 提交于 2021-01-24 08:46:51
问题 I'm trying to scrape a website via Scrapy. However, the website is extremely slow at times and it takes almost 15-20 seconds to respond at first request in browser. Anyways, sometimes, when I try to crawl the website using Scrapy, I keep getting TCP Timeout error. Even though the website opens just fine on my browser. Here's the message: 2017-09-05 17:34:41 [scrapy.downloadermiddlewares.retry] DEBUG: Gave up retrying <GET http://www.hosane.com/result/spec ialList> (failed 16 times): TCP

《Python 3网络爬虫开发实战》中文PDF+源代码+书籍软件包+崔庆才

由 南笙酒味 提交于 2021-01-23 03:48:12
《Python 3网络爬虫开发实战中文》PDF+源代码+书籍软件包+崔庆才 下载： 链接：https://pan.baidu.com/s/18yqCr7i9x_vTazuMPzL23Q 提取码：i79n 解压 密码：pythonlwhOO7007 本书书籍软件包为本人原创，在这个时间就是金钱的时代，有些软件下起来是很麻烦的，这个真的可以为你们节省很多时间。软件包包含了该书籍所需的所有软件。此文件大小为1.85G 这是一个非常ok，使下载速度到1.5MB左右这是一个百度网盘直链下载教程链接：http://www.360kuai.com/pc/9d1c911de5d52d039?cota=4&tj_url=so_rec&sign=360_57c3bbd1&refer_scene=so_1 但是现在直链被封了，但还可以用其中的高速下载 本书介绍了如何利用Python 3开发网络爬虫，书中首先介绍了环境配置和基础知识，然后讨论了urllib、requests、正则表达式、Beautiful Soup、XPath、pyquery、数据存储、Ajax数据爬取等内容，接着通过多个案例介绍了不同场景下如何实现数据爬取，后介绍了pyspider框架、Scrapy框架和分布式爬虫。 本书适合Python程序员阅读。 目录 来源： oschina 链接： https://my.oschina.net/u

How Can I Fix “TypeError: Cannot mix str and non-str arguments”?

由 。_饼干妹妹 提交于 2021-01-22 11:13:02
问题 I'm writing some scraping codes and experiencing an error as above. My code is following. # -*- coding: utf-8 -*- import scrapy from myproject.items import Headline class NewsSpider(scrapy.Spider): name = 'IC' allowed_domains = ['kosoku.jp'] start_urls = ['http://kosoku.jp/ic.php'] def parse(self, response): """ extract target urls and combine them with the main domain """ for url in response.css('table a::attr("href")'): yield(scrapy.Request(response.urljoin(url), self.parse_topics)) def

How Can I Fix “TypeError: Cannot mix str and non-str arguments”?

由 会有一股神秘感。 提交于 2021-01-22 11:00:47
问题 I'm writing some scraping codes and experiencing an error as above. My code is following. # -*- coding: utf-8 -*- import scrapy from myproject.items import Headline class NewsSpider(scrapy.Spider): name = 'IC' allowed_domains = ['kosoku.jp'] start_urls = ['http://kosoku.jp/ic.php'] def parse(self, response): """ extract target urls and combine them with the main domain """ for url in response.css('table a::attr("href")'): yield(scrapy.Request(response.urljoin(url), self.parse_topics)) def

Add a delay to a specific scrapy Request

由 耗尽温柔 提交于 2021-01-22 10:11:32
问题 Is it possible to delay the retry of a particular scrapy Request. I have a middleware which needs to defer the request of a page until a later time. I know how to do the basic deferal (end of queue), and also how to delay all requests (global settings), but I want to just delay this one individual request. This is most important near the end of the queue, where if I do the simple deferral it immediately becomes the next request again. 回答1: One way would be to add a middleware to your Spider

Add a delay to a specific scrapy Request

由 大憨熊 提交于 2021-01-22 10:10:45
问题 Is it possible to delay the retry of a particular scrapy Request. I have a middleware which needs to defer the request of a page until a later time. I know how to do the basic deferal (end of queue), and also how to delay all requests (global settings), but I want to just delay this one individual request. This is most important near the end of the queue, where if I do the simple deferral it immediately becomes the next request again. 回答1: One way would be to add a middleware to your Spider

Add a delay to a specific scrapy Request

由 醉酒当歌 提交于 2021-01-22 10:09:44
问题 Is it possible to delay the retry of a particular scrapy Request. I have a middleware which needs to defer the request of a page until a later time. I know how to do the basic deferal (end of queue), and also how to delay all requests (global settings), but I want to just delay this one individual request. This is most important near the end of the queue, where if I do the simple deferral it immediately becomes the next request again. 回答1: One way would be to add a middleware to your Spider

Add a delay to a specific scrapy Request

由 心不动则不痛 提交于 2021-01-22 10:09:24
问题 Is it possible to delay the retry of a particular scrapy Request. I have a middleware which needs to defer the request of a page until a later time. I know how to do the basic deferal (end of queue), and also how to delay all requests (global settings), but I want to just delay this one individual request. This is most important near the end of the queue, where if I do the simple deferral it immediately becomes the next request again. 回答1: One way would be to add a middleware to your Spider
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