Three Common Methods For Web Data Extraction

Three Common Methods For Web Data Extraction

Probably the most common technique used traditionally to extract data from web pages this is to cook up some regular expressions that match the pieces you want (e.g., URL's and link titles). Our screen-scraper software actually started out as an application written in Perl for this very reason. In addition to regular expressions, you might also use some code written in something like Java or Active Server Pages to parse out larger chunks of text. Using raw regular expressions to pull out the data can be a little intimidating to the uninitiated, and can get a bit messy when a script contains a lot of them. At the same time, if you're already familiar with regular expressions, and your scraping project is relatively small, they can be a great solution.

Other techniques for getting the data out can get very sophisticated as algorithms that make use of artificial intelligence and such are applied to the page. Some programs will actually analyze the semantic content of an HTML page, then intelligently pull out the pieces that are of interest. Still other approaches deal with developing "ontologies", or hierarchical vocabularies intended to represent the content domain.

There are a number of companies (including our own) that offer commercial applications specifically intended to do screen-scraping. The applications vary quite a bit, but for medium to large-sized projects they're often a good solution. Each one will have its own learning curve, so you should plan on taking time to learn the ins and outs of a new application. Especially if you plan on doing a fair amount of screen-scraping it's probably a good idea to at least shop around for a screen-scraping application, as it will likely save you time and money in the long run.

So what's the best approach to data extraction? It really depends on what your needs are, and what resources you have at your disposal. Here are some of the pros and cons of the various approaches, as well as suggestions on when you might use each one:

Raw regular expressions and code

Advantages:

- If you're already familiar with regular expressions and at least one programming language, this can be a quick solution.
- Regular expressions allow for a fair amount of "fuzziness" in the matching such that minor changes to the content won't break them.
- You likely don't need to learn any new languages or tools (again, assuming you're already familiar with regular expressions and a programming language).
- Regular expressions are supported in almost all modern programming languages. Heck, even VBScript has a regular expression engine. It's also nice because the various regular expression implementations don't vary too significantly in their syntax.

Ontologies and artificial intelligence

Advantages:

- You create it once and it can more or less extract the data from any page within the content domain you're targeting.
- The data model is generally built in. For example, if you're extracting data about cars from web sites the extraction engine already knows what the make, model, and price are, so it can easily map them to existing data structures (e.g., insert the data into the correct locations in your database).
- There is relatively little long-term maintenance required. As web sites change you likely will need to do very little to your extraction engine in order to account for the changes.

Screen-scraping software

Advantages:

- Abstracts most of the complicated stuff away. You can do some pretty sophisticated things in most screen-scraping applications without knowing anything about regular expressions, HTTP, or cookies.
- Dramatically reduces the amount of time required to set up a site to be scraped. Once you learn a particular screen-scraping application the amount of time it requires to scrape sites vs. other methods is significantly lowered.
- Support from a commercial company. If you run into trouble while using a commercial screen-scraping application, chances are there are support forums and help lines where you can get assistance.

Source:http://ezinearticles.com/?Three-Common-Methods-For-Web-Data-Extraction&id=165416

Scrape Data from Website is a Proven Way to Boost Business Profits

Data scraping is not a new technology in market. Several business persons use this method to get benefited from it and to make good fortune. It is the procedure of gathering worthwhile data that has been located in the public domain of the internet and keeping it in records or databases for future usage in innumerable applications.

There is a large amount of data available only through websites. However, as many people have found out, trying to copy data into a usable database or spreadsheet directly out of a website can be a tiring process. Manual copying and pasting of data from web pages is shear wastage of time and effort. To make this task easier there are a number of companies that offer commercial applications specifically intended to scrape data from website. They are proficient of navigating the web, evaluating the contents of a site, and then dragging data points and placing them into an organized, operational databank or worksheet.

Web scraping company

Every day, there are numerous websites that are hosting in internet. It is almost impossible to see all the websites in a single day. With this scraping tool, companies are able to view all the web pages in internet. If a business is using an extensive collection of applications, these scraping tools prove to be very useful.

It is most often done either to interface to a legacy system which has no other mechanism which is compatible with current hardware, or to interface to a third-party system which does not provide a more convenient API. In the second case, the operator of the third-party system will often see screen scraping as unwanted, due to reasons such as increased system load, the loss of advertisement revenue, or the loss of control of the information content.

Scrape data from website greatly helps in determining the modern market trends, customer behavior and the future trends and gathers relevant data that is immensely desirable for the business or personal use.


Source : http://www.botscraper.com/blog/Scrape-Data-from-Website-is-a-Proven-Way-to-Boost-Business-Profits

To Know Difference Of Data Mining And Web Screen Scraping

To Know Difference Of Data Mining And Web Screen Scraping

Screen scraping to find information, where data mining can analyze information possible. This is a great simplification, so I will work a bit.

World Fast Forward, screen scraping websites than ever refers to extract information. Computer programs "crawl" or "spider" through web sites, pulls the data. For many people the comparison shopping engine, archive web pages, or a spreadsheet for a text so that it can be filtered to analyze things like build to download.

Data mining, on the other hand, is defined by Wikipedia as "the practice of automatically search large stores of data for patterns. Other words, you already know, and you know about the useful things about care. Thus we have the right pages of text data mining, automated data collection, web data extraction, and the bloody website is preferred.

If your two-card Treasure popular poker forums and read to your poker "data mining" many of the technical discussion of the saw, and thought how it can help you win more money. In this article I will give you an introduction to poker data mining and clarify some common misconceptions.

Poker data mining is a process where you (I) is a poker hand histories ("Data") collected in the game without taking part yourself. After the collected hand, you Holder Manager, your opponents to play in a program like Advanced Statistics can import. Normally determine the player playing style.

In addition, many people enjoy watching the high stakes games and save your favorite poker professionals with the hand history. For a special "hand grabber" data mine the program. A hand grabber a small program that runs in the background and the “clock” poker table for your computer, and protects them from the hand history, if any are found.

Invisible Shield as hard and strong that even if you have a knife to try and cut on the screen, you will surely fail. For an expensive mobile phone, screen protector because of your unfailing security forces has the best security. Transparent cover can hardly be seen because it is very thin. But this does not mean that it is not difficult if the scratches and resists any form.

In fact, invisible shield, even if you close your eyes, hold the phone, you can hardly see. Degree of protection as their heavy armor, although seem thin and irrelevant. Invisible Shield is just a shell for the phone, the phone is not interrupted. If you have a cable that you connect to the touch screen as before to use.

It is possible for you to buy full body armor kit, which is a security for the phone. Screen coverage is absolutely necessary, and the slope of the touch screen can also be purchased. But for the kit to buy the entire cover of the phone because it marks or scratches from all sides to protect the whole phone is recommended.

Source:http://www.selfgrowth.com/articles/to-know-difference-of-data-mining-and-web-screen-scraping