Very often there arises the need for you to gather very large amounts of information for several purposes including marketing. For most businesses, gathering large amounts of data is actually an integral part of the marketing process. If you are to do this yourself or employ humans to do it, it will cost you so much and take so much time to accomplish. In this article we will look at one of the best ways for doing this at a fraction of both the cost and time. This method is known as web scraping. We at ExpertCoders.com can also help you with everything you need for successful web scraping.
Also known as screen scraping, web harvesting or web data extraction, web scraping refers to the automated processes carried out by a software (bot or web crawler) to scrape (copy or extract) data from a website. These software access the World Wide Web through an intermediary such as a browser or directly using the Hypertext Transfer Protocol. The data gathered and copied is saved to a file on a local machine (computer), or to a database or spreadsheet.
There are several reasons why you may want to scrape a website but they can all be summarized in one – you need to make use of the data. The data on websites are usually viewed through browsers but saving them automatically when needed is a functionality not offered by browsers.
To build any form of web page, a text-based mark-up language (XHTML or HTML) is used and these pages can often contain very essential or useful data which can be exploited for your needs. The majority of these pages are, however, designed to be readable to human end users in preference to automated use. This instantly leaves the option of the user manually copying the data himself. The problem with manually scraping data from the web is that it is a slow and very tedious process which makes automating the process a favorite.
Since manually copying data on websites is a tedious process it is natural to rely on software that can automate the process and accomplish is in a fraction of the time it will take a human to do it.
So back to our reasons for scraping the web: Some reasons for or uses of web scraping will include in monitoring and comparing prices online, data and web mining, monitoring of weather data, research, detecting changes in a website, integrating data into a website, monitoring your competitors by tracking and scraping product reviews, gathering of prospects contacts for a business, as a part of applications employed in web indexing, gathering listings for real estate, web mashup, and for tracking online reputation and presence.
A typical example of an occasion where web scraping will come into play would be that you need the names and Urls of certain companies you may intend to market a product to. But since getting them manually may be too hectic as there may be thousands of them, scraping the web for this information would be the best option. Another example is that you want the names and contact of people in a specific niche – people who have provided their bio details on other websites in the specific niche or one related to it.
As stated above it is possible to manually copy data you need from a web page. And although this is possible, copying out the information or data needed from websites manually is a very tedious process. This leaves you with the option of automating the process. To automate the process you will have to make use of a web scraper.
A web scraper can be describes as an Application Programming Interface (API) that is used in extracting data from a web page or website. Better still, you can say it’s a software with an API that allows you extract data from a web page. There have been several forms of web scraping but more recent forms involve data feeds from web servers to be ‘listened’ to.
Some websites, however, employ certain methods in preventing web scraping. These methods of prevention include the detection and disallowing of bots or web crawlers from crawling their web pages. Many web scraping systems, in response to this, apply techniques that rely on computer vision, DOM parsing, and natural language processing as a way of simulating human browsing so as to gather the content of web pages for offline parsing.
To scrape a web page, you need to get or download the page and then get the information from it. For you to view a web page with a browser, the browser, basically, has to download the page. This makes crawling the web an essential part of web scraping as web pages have to be fetched for use at a time different from when they were gotten. When the pages of the website in question have been fetched, extraction can then begin taking place. The web page’s content can be searched, parsed or even reformatted with the extracted data saved into spreadsheets on a local computer or into databases in a server.
While there are many web scraping software available in the market, there is no ‘one size fits all’ that you can rely upon for any need you want. This is because data structure differs from website to website. The best software solutions are those that are built specifically for scraping the website you want scraped. This is why you need ExpertCoders to build a web scraper for you. The web scraper we design will match the data structure of the websites you want to harvest. And if you need one that recognizes different data structures, we will have that built for you too.
There are several techniques employed in web scraping. These range from fully automated techniques to ad-hoc or human copying of the data needed but each technique has its limitations. Some of them include:
- Human copy and paste: As the name indicates, this involves someone manually copying and pasting the needed data from the target web page or website.
- Text pattern matching: This involves using the regular expression matching abilities of certain programming languages like Python, Perl etc to match and extract the target data. This approach is very simple and it is equally as powerful.
- Http programming: This involves the use of socket programming to retrieve both dynamic and static web pages from a remote web server by posting Http request to the server.
- Html parsing: This technique exploits the fact that many websites display or put data within templates. Different data types are categorized and put within separate templates. Web pages that display similar data types are encoded with similar templates. It is this structure that is exploited in Html parsing.
Other techniques used in web scraping include Computer vision web-page analysis, Semantic annotation recognizing, Vertical aggregation, and DOM parsing.
With the introduction of Beautiful Soup in 2004, harvesting the web got even easier. Before this time scraping websites was limited to websites that offered APIs to access their public data. But with Beautiful Soup, the most sophisticated and advanced library, designed for Python, parsing content from within the HTML container of websites that do not offer any APIs became possible. Thus, some of the best web scrapers are written in Python and Python is our programming language of choice here at ExpertCoders.com
You can get a web scraper built for you here at ExpertCoder.com. The web scrapers we build will always be tailored to meet your needs. Even if you need one that is configured for multiple websites, we are still the developers you need as we will build one that is custom made for the websites you will be picking. Other generic web scrapers are built for just about any website and so are mostly inefficient. Since you will be specifying to us the data types you want to extract before we build, the one we build for you will have the ability to effectively harvest that data. We will also build a web scraper that is user friendly and intuitive.
Irrespective of the business you run, to stand out or even lead the competition, you will have need of data for different purposes as specified above. This data would have to be extracted from different sources or web pages available on the internet. Doing this manually will prove to be a cost intensive effort. This is where a web scraper comes in. But since there are different data types and a generic web scraper will be inefficient for scraping every data type or web page, a custom made web scraper is the best option for your business or even personal use.