Defaults to mechanize.Request; contentparser – A function that is responsible for parsing received html/xhtml content. See the builtin mechanize.html.contentparser function for details on the interface this function must support. Factoryclass – HTML Factory class to use. Defaults to mechanize.Factory. Mechanize is a ruby library that makes automated web interaction easy. sparklemotion/mechanize. #. Mac Safari 4 #. Mechanize (default) #. Windows IE 6 #. Windows IE 7 #. Windows IE 8. # Note that for Mechanize::Download subclasses, the maximum buffer size. Mar 02, 2012.
Web Scraping can most succintly be described as 'Creating an API where there is none'. It is mainly used to harvest data from the web that cannot be easily downloaded manually/does not provide an option for direct download. Scraped data can be used for a variety of purposes like online price comaprison, detecting changes in web page content, real-time data integration and web mashups.
Scripting languages are best suited for web scraping as they provide an interactive interpreter which helps a lot when you are developing the scraper. The option to try out new Xpath combinations and being able to get instant feedback saves a huge amout of time while developing. Scripting languages like Python, Ruby and Perl are popular choices for web scraping. These languages also have a large number of libraries that help in fetching and extracting data.
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Most of the popular libraries like 'Mechanize' have been ported to most of the popular scripting languages. We have chosen 'Ruby' Language here since it offers a solid set of libraries, comprehensive documentation, and a huge user base.
Considerations before Web Scraping
The first two questions can easily be answered by consulting the robots.txt file/reading the website's terms and condtions or contacting the website administrators.
In this article, we will be scraping all the Reference Links and the Further Reading text from wikipedia Ruby language introduction page using Mechanize and Nokogiri gems.
Mechanize will primarily be used to fetch the pages and Nokogiri will be used to find specific elements to extract from the page. Mechanize can be used to do a lot of cool things like submitting a form, following links in a page and so on. But, for the purpose of this tutorial, it will only be used to fetch the html markup. The url of the page which has to be scraped will be sent as a command line argument to the script.
Tools used
First things first, you will need the following Ruby version and Ruby gems to be installed on your machine.
Installing Ruby Language
If you are using Windows, you can downloaed a binary installation file from the official Ruby website and install it.
If you are using Ubuntu, then the following command will install Ruby 1.9.3 on your machine.
Installing Mechanize gemDownload Mechanize For Ruby Machine LearningInstalling Nokogiri gem
That's it. That is all you need to start scraping (most) of the web.
Code
The following section shows the code that this tutorial uses. We have named our file as 'scraper.rb' since Ruby language uses the '.rb' extension.
scraper.rbMechanize DocumentationScript usage
To run the script, navigate to the directory where you have stored the source file(scraper.rb) and execute the following command.
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Find out our guide on Code Description
Let's look at the explanation for the code line by line. Tempat download aplikasi gratis untuk mac.
Web Scraping considerations.
Free download game of throne season 7 episode 1. Here are a few considerations that you have to keep in mind when you are scraping the data.
Check if there is already an API in place. Always.
Wikipedia for example, already has an API through which you can get all the required data. API is a much cleaner and faster way to access data and the website servers will also have an easier time. We chose wikipedia for this tutorial simply because it has good structured html content and all the data is in public domain already.
Make sure you are not consuming the server resources greedily.
Serving pages on the web takes some amount of resources and it is easy for a server to get bogged down if there are too many requests. Make sure that you put a limit on the number of requests that you send per specific amount of time.
Always make sure that you follow the TOS of the site.
Websites usually have a set of rules that you have to follow once you get their data. Some websites may have a limit on how long you can store the data on your machine/how you can use their data. Being aware of their TOS and use the data accordingly.
Download Mechanize For Ruby Macos
There we go. That was a small and quick introduction to the world of Web Scraping and the Mechanize and Nokogiri gems.
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Web Scraping with Ruby using Mechanize and Nokogiri gems - @icicletechhttp://t.co/RvWrTR15yj
— Icicle (@icicletech) November 7, 2013
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Maybe it is because I’m kinda new to Ruby, but this took me awhile to find. I wanted to build a Ruby script that can check just the HTTP status code for an array of urls.
To handle a lot of the dirty work I used the following gems
Nokogiri, and Open-URI to grab a sitemap.xml file and parse it, and Mechanize to check the http status code
https://cardever283.weebly.com/best-free-download-app-mac.html. Ok, build the code to grab a sitemap.xml and parse the urls into an array was easy.
Mechanize Gem
I know I could have check the http status code from the xpath each, but I plan on doing a few things to the array of url not just the single check.
At this point I have an array of urls. Now I need to check the HTTP status of each one…
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After instanciating the mechanize class, I iterate through the array and perform a “head” call to checek the status of each url. In the result object that is returned the http status of the request is in the property called code. I make sure that code is an integer (to_i) and then compare it to 200, if it equals 200 it is good.
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I’m really starting to dig Ruby !!!
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