Saturday, 28 September 2013

Visual Web Ripper: Using External Input Data Sources

Sometimes it is necessary to use external data sources to provide parameters for the scraping process. For example, you have a database with a bunch of ASINs and you need to scrape all product information for each one of them. As far as Visual Web Ripper is concerned, an input data source can be used to provide a list of input values to a data extraction project. A data extraction project will be run once for each row of input values.

An input data source is normally used in one of these scenarios:

    To provide a list of input values for a web form
    To provide a list of start URLs
    To provide input values for Fixed Value elements
    To provide input values for scripts

Visual Web Ripper supports the following input data sources:

    SQL Server Database
    MySQL Database
    OleDB Database
    CSV File
    Script (A script can be used to provide data from almost any data source)

To see it in action you can download a sample project that uses an input CSV file with Amazon ASIN codes to generate Amazon start URLs and extract some product data. Place both the project file and the input CSV file in the default Visual Web Ripper project folder (My Documents\Visual Web Ripper\Projects).

For further information please look at the manual topic, explaining how to use an input data source to generate start URLs.


Source: http://extract-web-data.com/visual-web-ripper-using-external-input-data-sources/

Thursday, 26 September 2013

Using External Input Data in Off-the-shelf Web Scrapers

There is a question I’ve wanted to shed some light upon for a long time already: “What if I need to scrape several URL’s based on data in some external database?“.

For example, recently one of our visitors asked a very good question (thanks, Ed):

    “I have a large list of amazon.com asin. I would like to scrape 10 or so fields for each asin. Is there any web scraping software available that can read each asin from a database and form the destination url to be scraped like http://www.amazon.com/gp/product/{asin} and scrape the data?”

This question impelled me to investigate this matter. I contacted several web scraper developers, and they kindly provided me with detailed answers that allowed me to bring the following summary to your attention:
Visual Web Ripper

An input data source can be used to provide a list of input values to a data extraction project. A data extraction project will be run once for each row of input values. You can find the additional information here.
Web Content Extractor

You can use the -at”filename” command line option to add new URLs from TXT or CSV file:

    WCExtractor.exe projectfile -at”filename” -s

projectfile: the file name of the project (*.wcepr) to open.
filename – the file name of the CSV or TXT file that contains URLs separated by newlines.
-s – starts the extraction process

You can find some options and examples here.
Mozenda

Since Mozenda is cloud-based, the external data needs to be loaded up into the user’s Mozenda account. That data can then be easily used as part of the data extracting process. You can construct URLs, search for strings that match your inputs, or carry through several data fields from an input collection and add data to it as part of your output. The easiest way to get input data from an external source is to use the API to populate data into a Mozenda collection (in the user’s account). You can also input data in the Mozenda web console by importing a .csv file or importing one through our agent building tool.

Once the data is loaded into the cloud, you simply initiate building a Mozenda web agent and refer to that Data list. By using the Load page action and the variable from the inputs, you can construct a URL like http://www.amazon.com/gp/product/%asin%.
Helium Scraper

Here is a video showing how to do this with Helium Scraper:


The video shows how to use the input data as URLs and as search terms. There are many other ways you could use this data, way too many to fit in a video. Also, if you know SQL, you could run a query to get the data directly from an external MS Access database like
SELECT * FROM [MyTable] IN "C:\MyDatabase.mdb"

Note that the database needs to be a “.mdb” file.
WebSundew Data Extractor
Basically this allows using input data from external data sources. This may be CSV, Excel file or a Database (MySQL, MSSQL, etc). Here you can see how to do this in the case of an external file, but you can do it with a database in a similar way (you just need to write an SQL script that returns the necessary data).
In addition to passing URLs from the external sources you can pass other input parameters as well (input fields, for example).
Screen Scraper

Screen Scraper is really designed to be interoperable with all sorts of databases. We have composed a separate article where you can find a tutorial and a sample project about scraping Amazon products based on a list of their ASINs.


Source: http://extract-web-data.com/using-external-input-data-in-off-the-shelf-web-scrapers/

Wednesday, 25 September 2013

A simple way to turn a website into JSON

Recently, while surfing the web I stumbled upon an simple web scraping service named Web Scrape Master. It is a kind of RESTful web service that extracts data from a specified web site and returns it to you in JSON format.
How it works

Though I don’t know what this service may be useful for, I still like its simplicity: all you need to do is to make an HTTP GET request, passing all necessary parameters in the query string:
http://webscrapemaster.com/api/?url={url}&xpath={xpath}&attr={attr}&callback={callback}

    url  - the URL of the website you want to scrape
    xpath – xpath determining the data you need to extract
    attr - attribute the name you need to get the value of (optional)
    callback - JSON callback function (optional)

For example, for the following request to our testing ground:

http://webscrapemaster.com/api/?url=http://testing-ground.extract-web-data.com/blocks&xpath=//div[@id=case1]/div[1]/span[1]/div

You will get the following response:

[{"text":"<div class='name'>Dell Latitude D610-1.73 Laptop Wireless Computer</div>","attrs":{"class":"name"}}]
Visual Web Scraper

Also, this service offers a special visual tool for building such requests. All you need to do is to enter the URL of the website and click to the element you need to scrape:
Visual Web Scraper
Conclusion

Though I understand that the developer of this service is attempting to create a simple web scraping service, it is still hard to imagine where it can be useful. The task that the service does can be easily accomplished by means of any language.

Probably if you already have software receiving JSON from the web, and you want to feed it with data from some website, then you may find this service useful. The other possible application is to hide your IP when you do web scraping. If you have other ideas, it would be great if you shared them with us.



Source: http://extract-web-data.com/a-simple-way-to-turn-a-website-into-json/

Tuesday, 24 September 2013

Selenium IDE and Web Scraping

Selenium is a browser automation framework that includes IDE, Remote Control server and bindings of various flavors including Java, .Net, Ruby, Python and other. In this post we touch on the basic structure of the framework and its application to  Web Scraping.
What is Selenium IDE


Selenium IDE is an integrated development environment for Selenium scripts. It is implemented as a Firefox plugin, and it allows recording browsers’ interactions in order to edit them. This works well for software tests, composing and debugging. The Selenium Remote Control is a server specific for a particular environment; it causes custom scripts to be implemented for controlled browsers. Selenium deploys on Windows, Linux, and iOS. How various Selenium components are supported with major browsers read here.
What does Selenium do and Web Scraping

Basically Selenium automates browsers. This ability is no doubt to be applied to web scraping. Since browsers (and Selenium) support JavaScript, jQuery and other methods working with dynamic content why not use this mix for benefit in web scraping, rather than to try to catch Ajax events with plain code? The second reason for this kind of scrape automation is browser-fasion data access (though today this is emulated with most libraries).

Yes, Selenium works to automate browsers, but how to control Selenium from a custom script to automate a browser for web scraping? There are Selenium PHP and other language libraries (bindings) providing for scripts to call and use Selenium. It is possible to write Selenium clients (using the libraries) in almost any language we prefer, for example Perl, Python, Java, PHP etc. Those libraries (API), along with a server, the Java written server that invokes browsers for actions, constitute the Selenum RC (Remote Control). Remote Control automatically loads the Selenium Core into the browser to control it. For more details in Selenium components refer to here.



A tough scrape task for programmer

“…cURL is good, but it is very basic.  I need to handle everything manually; I am creating HTTP requests by hand.
This gets difficult – I need to do a lot of work to make sure that the requests that I send are exactly the same as the requests that a browser would
send, both for my sake and for the website’s sake. (For my sake
because I want to get the right data, and for the website’s sake
because I don’t want to cause error messages or other problems on their site because I sent a bad request that messed with their web application).  And if there is any important javascript, I need to imitate it with PHP.
It would be a great benefit to me to be able to control a browser like Firefox with my code. It would solve all my problems regarding the emulation of a real browser…
it seems that Selenium will allow me to do this…” -Ryan S

Yes, that’s what we will consider below.
Scrape with Selenium

In order to create scripts that interact with the Selenium Server (Selenium RC, Selenium Remote Webdriver) or create local Selenium WebDriver script, there is the need to make use of language-specific client drivers (also called Formatters, they are included in the selenium-ide-1.10.0.xpi package). The Selenium servers, drivers and bindings are available at Selenium download page.
The basic recipe for scrape with Selenium:

    Use Chrome or Firefox browsers
    Get Firebug or Chrome Dev Tools (Cntl+Shift+I) in action.
    Install requirements (Remote control or WebDriver, libraries and other)
    Selenium IDE : Record a ‘test’ run thru a site, adding some assertions.
    Export as a Python (other language) script.
    Edit it (loops, data extraction, db input/output)
    Run script for the Remote Control

The short intro Slides for the scraping of tough websites with Python & Selenium are here (as Google Docs slides) and here (Slide Share).
Selenium components for Firefox installation guide

For how to install the Selenium IDE to Firefox see  here starting at slide 21. The Selenium Core and Remote Control installation instructions are there too.
Extracting for dynamic content using jQuery/JavaScript with Selenium

One programmer is doing a similar thing …

1. launch a selenium RC (remote control) server
2. load a page
3. inject the jQuery script
4. select the interested contents using jQuery/JavaScript
5. send back to the PHP client using JSON.

He particularly finds it quite easy and convenient to use jQuery for
screen scraping, rather than using PHP/XPath.
Conclusion

The Selenium IDE is the popular tool for browser automation, mostly for its software testing application, yet also in that Web Scraping techniques for tough dynamic websites may be implemented with IDE along with the Selenium Remote Control server. These are the basic steps for it:

    Record the ‘test‘ browser behavior in IDE and export it as the custom programming language script
    Formatted language script runs on the Remote Control server that forces browser to send HTTP requests and then script catches the Ajax powered responses to extract content.

Selenium based Web Scraping is an easy task for small scale projects, but it consumes a lot of memory resources, since for each request it will launch a new browser instance.



Source: http://extract-web-data.com/selenium-ide-and-web-scraping/

Monday, 23 September 2013

Data Entry Services to Ease Your Workload

Data entry outsourcing has been practised from many years. Since two decades, data conversion or data processing has been done from home or at BPO centers by certified persons but it costs too high. Although it's normally a fine idea to keep on data entry in-house, occasionally it makes more sense to outsource it.

A few years back, there were few companies acknowledged about outsourcing their work, and from that time this field has developed quickly in the market and generating better and better solutions. It was considered that only in-house personnel could really understand the company's productions, but nowadays there are specialists who are well-educated in every field of business. They can bring off data better and faster. Outsourcing also lessens employee strain and management troubles.

For instance, you are carrying a one-time customer survey on service quality and anticipating a written response from thousands of buyers but you do not have the sufficient faculty to do the BPO work or you've to pay off high to the experts for the work, in that case outsourcing would be more cost-efficient.By outsourcing the BPO work, you'll be able to avoid some additional expenses.

Key to acquire success in outsourcing is to discover suitable BPO service provider. The selected BPO service supplier should have experience of field and well apprehension of data entry. The service provider should also volunteer a variety of profits concerning formulas of data transmission, turnaround etc. The most effective service provider will even help to plan project and give some propositions for reducing the costs.

Outsourcing BPO work profits you financially as well as strategically. BPO outsourcing gives way benefits by rendering time and cost which allow you to step-up you business productiveness. Many people would like to outsource their work due to high-ranking of accuracy and low level of price. Particularly trained professional person from offshore nations furnish you first-class services with important suggestions. There are numerous advantages of BPO outsourcing some major rewards are:

Advantage of affordable services
Firm delivery
Access of specified service
Focusing energy and manpower on your core business
Save workforce and training tolls
Increased client satisfaction

Data entry services admit simple text BPO work to alphameric entries calls for complex computations. To cope with the high flow of data entry work a lot of houses use advanced word processing software and engage skilled professional in fast keyboard controlling.

Business process outsourcing units pursued in allowing data entry services give quick, well-organized and protected data entry solutions to hold their place in competitive outsourcing market. Many administrations supply high level of accuracy with all over confidentiality. These companies also employ the services of proofreaders in an attempt to give high precise data entry service.

Now, your business ambitions can be fulfilled without blocking your working capital with Please visit BPO Companies for more information.




Source: http://ezinearticles.com/?Data-Entry-Services-to-Ease-Your-Workload&id=4970827

Friday, 20 September 2013

Outsource Your Data Entry Work to Developing Nations

To manage data systematically is a herculean task for all organizations especially for the growing ones. Several Asian countries including India have become a hub for providing outsourcing services. Data entry services remains on the top when it comes to outsourcing to India.

By outsourcing to developing nations as India will be helpful to organizations to maintain details as well as daily records systematically. There are a huge number of well-known firms in India that deals with data entry services. These companies have proficient and well qualified staff to aptly manage your business data. Staff are highly skilled and updated with the latest technologies to meet desired goals.

Services offered by these organizations are both online as well as offline. To manage data from ebooks, image files, as well as web browsers are part of online, whereas to manage data received in the form of papers, documents, as well as directories is part of offline. You will get the most apt solution by outsourcing to India. These companies also provide you free trial of their data entering services before taking up your actual outsourcing projects. You can also avail services in other areas such as Word conversion, data conversion, PDF conversion plus OCR clean up.

Save up to 40-60% on cost on business operations by outsourcing to developing countries as India. Outsourcing is helpful in bringing down the cost which could be better invested in the expansion of your business.

You can outsource your projects to data entry services irrespective of the business industry you are into, such as finance, retail, real estate, or lodging outsourcing will be helpful to you. You can reduce the workload of your employees by outsourcing your data entry tasks which would be beneficial in improving their competence as well as efficiency. This takes your business in the front position as it greatly cuts down the labor cost without affecting quality.





Source: http://ezinearticles.com/?Outsource-Your-Data-Entry-Work-to-Developing-Nations&id=5901946