How Xpath Plays Vital Role In Web Scraping

How Xpath Plays Vital Role In Web Scraping

XPath is a language for finding information in structured documents like XML or HTML. You can say that XPath is (sort of) SQL for XML or HTML files. XPath is used to navigate through elements and attributes in an XML or HTML document.

To understand XPath we must be clear about elements and nodes which are the building blocks of XML and HTML. Let’s talk about them. Here is an example element in an HTML document:

   <a class=”hyperlink” href=http://www.google.com>google</a>

Copy the above text to a file, name it as sample.html and open it in a browser. This will end up as a text link displaying the words “google” and it will take you to www.google.com. For each element there are three main parts: The type, the attributes, andthe text. They are listed below:

 a                                 Type
class,  href                Attributes
google                       Text

Let’s grab some XPath developer tools. I am on Firebug for Firefox or you can use Chrome’s developer tools. We will now form some XPath expressions to extract data from the above element. We will also verify the XPath by using Firebug Console.

For extracting the text “google”:

   //a[@href]/text()   

   //a[@class=”hyperlink”]/text()
 
For extracting the hyperlink i.e. ”www.google.com” :

   //a/@href
//a[@class=”hyperlink”]/@href

That’s all with a single element but in reality, you need to deal with more complex forms.

Let’s proceed to the idea of nodes, and its familial relationship of HTML elements. Look at this example code:

 <div title=”Section1″>

   <table id=”Search”>

       <tr class=”Yahoo”>Yahoo Search</tr>

       <tr class=”Google”>Google Search</tr>

   </table>

</div>

 Notice the </div> at the bottom? That means the table and tr elements are contained within the div. These other elements are considered descendants of the div. The table is a child, and the tr is a grandchild (and so on and so forth). The two tr elements are considered siblings each other. This is vital, as XPath uses these relationships to find your element.

So suppose you want to find the Google item. Any of the following expressions will work:

   //tr[@class=’Google’]
   //div/table/tr[2]
  //div[@title=”Section1″]//tr

So let’s analyze the expressions. We start at the top element (also known as a node). The // means to search all descendants, / means to just look at the current element’s children. So //div means look through all descendants for a div element. The brackets [] specify something about that element. So we can look for an attribute with the @ symbol, or look for text with the text() function. We can chain as many of these together as we can.

Here is a quick reference:

   //             Search all descendant elements
   /              Search all child elements
   []             The predicate (specifies something about the element you are looking for)
   @           Specifies an element attribute. (For example, @title)
   
   .               Specifies the current node (useful when you want to look for an element’s children in the predicate)
   ..              Specifies the parent node
  text()       Gets the text of the element.
   
In the context of web scraping, XPath is a nice tool to have in your belt, as it allows you to write specifications of document locations more flexibly than CSS selectors.

Please subscribe to our blog to get notified when we publish the next blog post.

Source: http://blog.datahut.co/how-xpath-plays-vital-role-in-web-scraping/

Data Mining Process - Why Outsource Data Mining Service?

Data Mining Process - Why Outsource Data Mining Service?

Overview of Data Mining and Process:
Data mining is one of the unique techniques for investigating information to extract certain data patterns and decide to outcome of existing requirements. Data mining is widely use in client research, services analysis, market research and so on. It is totally based on mathematical algorithm and analytical skills to drive the desired results from the huge database collection.

Information mining is mostly used by financial analyzer, business and professional organization and also there are many growing area of business that are get maximum advantages of data extract with use of data warehouses in their small to large level of businesses.

Most of functionalities which are used in information collecting process define as under:

* Retrieving Data

* Analyzing Data

* Extracting Data

* Transforming Data

* Loading Data

* Managing Databases

Most of small, medium and large levels of businesses are collect huge amount of data or information for analysis and research to develop business. Such kind of large amount will help and makes it much important whenever information or data required.

Why Outsource Data Online Mining Service?

Outsourcing advantages of data mining services:
o Almost save 60% operating cost
o High quality analysis processes ensuring accuracy levels of almost 99.98%
o Guaranteed risk free outsourcing experience ensured by inflexible information security policies and practices
o Get your project done within a quick turnaround time
o You can measure highly skilled and expertise by taking benefits of Free Trial Program.
o Get the gathered information presented in a simple and easy to access format

Thus, data or information mining is very important part of the web research services and it is most useful process. By outsource data extraction and mining service; you can concentrate on your co relative business and growing fast as you desire.

Outsourcing web research is trusted and well known Internet Market research organization having years of experience in BPO (business process outsourcing) field.

If you want to more information about data mining services and related web research services, then contact us.

Source: http://ezinearticles.com/?Data-Mining-Process---Why-Outsource-Data-Mining-Service?&id=3789102

Web Scraping with Python: A Beginner’s Guide

Web Scraping with Python: A Beginner’s Guide

In the Big Data world, Web Scraping or Data extraction services are the primary requisites for Big Data Analytics. Pulling up data from the web has become almost inevitable for companies to stay in business. Next question that comes up is how to go about web scraping as a beginner.

Data can be extracted or scraped from a web source using a number of methods. Popular websites like Google, Facebook, or Twitter offer APIs to view and extract the available data in a structured manner.  This prevents the use of other methods that may not be preferred by the API provider. However, the demand to scrape a website arises when the information is not readily offered by the website. Python, an open source programming language is often used for Web Scraping due to its simple and rich ecosystem. It contains a library called “BeautifulSoup” which carries on this task. Let’s take a deeper look into web scraping using python.

Setting up a Python Environment:

To carry out web scraping using Python, you will first have to install the Python Environment, which enables to run code written in the python language. The libraries perform data scraping;

Beautiful Soup is a convenient-to-use python library. It is one of the finest tools for extracting information from a webpage. Professionals can scrape information from web pages in the form of tables, lists, or paragraphs. Urllib2 is another library that can be used in combination with the BeautifulSoup library for fetching the web pages. Filters can be added to extract specific information from web pages. Urllib2 is a Python module that can fetch URLs.

For MAC OSX :

To install Python libraries on MAC OSX, users need to open a terminal win and type in the following commands, single command at a time:

sudoeasy_install pip

pip install BeautifulSoup4

pip install lxml

For Windows 7 & 8 users:

Windows 7 & 8 users need to ensure that the python environment gets installed first. Once, the environment is installed, open the command prompt and find the way to root C:/ directory and type in the following commands:

easy_install BeautifulSoup4

easy_installlxml

Once the libraries are installed, it is time to write data scraping code.

Running Python:

Data scraping must be done for a distinct objective such as to scrape current stock of a retail store. First, a web browser is required to navigate the website that contains this data. After identifying the table, right click anywhere on it and then select inspect element from the dropdown menu list. This will cause a window to pop-up on the bottom or side of your screen displaying the website’s html code. The rankings appear in a table. You might need to scan through the HTML data until you find the line of code that highlights the table on the webpage.

Python offers some other alternatives for HTML scraping apart from BeautifulSoup. They include:

    Scrapy
    Scrapemark
    Mechanize

 Web scraping converts unstructured data from HTML code into structured form such as tabular data in an Excel worksheet. Web scraping can be done in many ways ranging from the use of Google Docs to programming languages. For people who do not have any programming knowledge or technical competencies, it is possible to acquire web data by using web scraping services that provide ready to use data from websites of your preference.

HTML Tags:

To perform web scraping, users must have a sound knowledge of HTML tags. It might help a lot to know that HTML links are defined using anchor tag i.e. <a> tag, “<a href=“http://…”>The link needs to be here </a>”. An HTML list comprises <ul> (unordered) and <ol> (ordered) list. The item of list starts with <li>.

HTML tables are defined with<Table>, row as <tr> and columns are divided into data as <td>;

    <!DOCTYPE html> : A HTML document starts with a document type declaration
    The main part of the HTML document in unformatted, plain text is defined by <body> and </body> tags
    The headings in HTML are defined using the heading tags from <h1> to <h5>
    Paragraphs are defined with the <p> tag in HTML
    An entire HTML document is contained between <html> and </html>

Using BeautifulSoup in Scraping:

While scraping a webpage using BeautifulSoup, the main concern is to identify the final objective. For instance, if you would like to extract a list from webpage, a step wise approach is required:

    First and foremost step is to import the required libraries:

 #import the library used to query a website

import urllib2

#specify the url wiki = “https://”

#Query the website and return the html to the variable ‘page’

page = urllib2.urlopen(wiki)

#import the Beautiful soup functions to parse the data returned from the website

from bs4 import BeautifulSoup

#Parse the html in the ‘page’ variable, and store it in Beautiful Soup format

soup = BeautifulSoup(page)

    Use function “prettify” to visualize nested structure of HTML page
    Working with Soup tags:

Soup<tag> is used for returning content between opening and closing tag including tag.

    In[30]:soup.title

 Out[30]:<title>List of Presidents in India till 2010 – Wikipedia, the free encyclopedia</title>

    soup.<tag>.string: Return string within given tag
    In [38]:soup.title.string
    Out[38]:u ‘List of Presidents in India and Brazil till 2010 in India – Wikipedia, the free encyclopedia’
    Find all the links within page’s <a> tags: Tag a link using tag “<a>”. So, go with option soup.a and it should return the links available in the web page. Let’s do it.
    In [40]:soup.a

Out[40]:<a id=”top”></a>

    Find the right table:

As a table to pull up information about Presidents in India and Brazil till 2010 is being searched for, identifying the right table first is important. Here’s a command to scrape information enclosed in all table tags.

all_tables= soup.find_all(‘table’)

Identify the right table by using attribute “class” of table needs to filter the right table. Thereafter, inspect the class name by right clicking on the required table of web page as follows:

    Inspect element
    Copy the class name or find the class name of right table from the last command’s output.

 right_table=soup.find(‘table’, class_=’wikitable sortable plainrowheaders’)

right_table

That’s how we can identify the right table.

    Extract the information to DataFrame: There is a need to iterate through each row (tr) and then assign each element of tr (td) to a variable and add it to a list. Let’s analyse the Table’s HTML structure of the table. (extract information for table heading <th>)

To access value of each element, there is a need to use “find(text=True)” option with each element.  Finally, there is data in dataframe.

There are various other ways to scrape data using “BeautifulSoup” that reduce manual efforts to collect data from web pages. Code written in BeautifulSoup is considered to be more robust than the regular expressions. The web scraping method we discussed use “BeautifulSoup” and “urllib2” libraries in Python. That was a brief beginner’s guide to start using Python for web scraping.

Source: https://www.promptcloud.com/blog/web-scraping-python-guide

Data Mining vs Screen-Scraping

Data mining isn't screen-scraping. I know that some people in the room may disagree with that statement, but they're actually two almost completely different concepts.

In a nutshell, you might state it this way: screen-scraping allows you to get information, where data mining allows you to analyze information. That's a pretty big simplification, so I'll elaborate a bit.

The term "screen-scraping" comes from the old mainframe terminal days where people worked on computers with green and black screens containing only text. Screen-scraping was used to extract characters from the screens so that they could be analyzed. Fast-forwarding to the web world of today, screen-scraping now most commonly refers to extracting information from web sites. That is, computer programs can "crawl" or "spider" through web sites, pulling out data. People often do this to build things like comparison shopping engines, archive web pages, or simply download text to a spreadsheet so that it can be filtered and analyzed.

Data mining, on the other hand, is defined by Wikipedia as the "practice of automatically searching large stores of data for patterns." In other words, you already have the data, and you're now analyzing it to learn useful things about it. Data mining often involves lots of complex algorithms based on statistical methods. It has nothing to do with how you got the data in the first place. In data mining you only care about analyzing what's already there.

The difficulty is that people who don't know the term "screen-scraping" will try Googling for anything that resembles it. We include a number of these terms on our web site to help such folks; for example, we created pages entitled Text Data Mining, Automated Data Collection, Web Site Data Extraction, and even Web Site Ripper (I suppose "scraping" is sort of like "ripping"). So it presents a bit of a problem-we don't necessarily want to perpetuate a misconception (i.e., screen-scraping = data mining), but we also have to use terminology that people will actually use.

Source: http://ezinearticles.com/?Data-Mining-vs-Screen-Scraping&id=146813

How to do data scraping from PDF files using PHP?

How to do data scraping from PDF files using PHP?

Situations arise when you want to scrap data from PDF or want to search PDF files for matching text. Suppose you have website where users uploads PDF files and you want to give search functionality to user which searches all uploaded PDF file content for matching text and show all PDFs that contains matching search keywords.

Or you might have all London real estate properties details in PDF report file and you want to quickly grab scrape data from PDF reports then you might need PDF scraping library.

To integrate such functionality to web application is not similar to normal search functionality that we do with database search.

Here is the straight solution for this problem. This involves PDF Data Scraping to plain text and match search terms. I have written this post for the people who want to do PDF data scraping or want to make their PDF files to be Searchable.

We are going to use class named class.pdf2text.php which converts PDF text to into ASCII text, so the class is known for PDF extraction. This PHP class ignores anything in PDF that is not a text.

Let’s see very basic example (Taken from author’s file):

<?php

include "class.pdf2text.php";

$a = new PDF2Text();
$a->setFilename('web-scraping-service.pdf'); //grab the pdf file reside in folder where PHP files resides.

$a->decodePDF();//converts PDF content to text
echo $a->output();

?>

“Web Scraping is a technique using which programmer can automate the copy paste manual work and save the time. This is PDF w eb scraping using PHP. We at Web Data Scraping offer Web Scraping and Data Scraping Service. Vist our website www.webdata-scraping.com”

For more complex extraction you can apply regular expression on the text you get and can parse text that you want from PDF. But keep in mind this has limitation and do not work with all types of PDF extraction.

But the wonderful use of this class is to make utility that allow user to search inside PDF when they search on web search bar. Last but not least, You can also find many PDF scraping software available in market that can do complex scraping from PDF files.

Source: http://webdata-scraping.com/data-scraping-pdf-files-using-php/

Things to take care while doing Web Scraping!!!

Things to take care while doing Web Scraping!!!

In the present day and age, web scraping word becomes most popular in data science. Basically web scraping is extracting the information from the websites using pre-written programs and web scraping scripts. Many organizations have successfully used web site scraping to build relevant and useful database that they use on a daily basis to enhance their business interests. This is the age of the Big Data and web scraping is one of the trending techniques in the data science.

Throughout my journey of learning web scraping and implementing many successful scraping projects, I have come across some great experiences we can learn from.  In this post, I’m going to discuss some of the approaches to take and approaches to avoid while executing web scraping.

User Proxies: Anonymously scraping data from websites

One should not scrape website with a single IP Address. Because when you repeatedly request the web page for web scraping, there is a chance that the remote web server might block your IP address preventing further request to the web page. To overcome this situation, one should scrape websites with the help of proxy servers (anonymous scraping). This will minimize the risk of getting trapped and blacklisted by a website. Use of Proxies to hide your identity (network details) to remote web servers while scraping data. You may also use a VPN instead of proxies to anonymously scrape websites.

Take maximum data and store it.

Do not follow “process the web page as it comes from the remote server”. Instead take all the information and store it to disk. This approach will be useful when your scraping algorithm breaks in the middle. In this case you don’t have to start scraping again. Never download the same content more than once as you are just wasting bandwidth. Try and download all content to disk in one go and then do the processing.

Follow strict rules in parsing:

Check various rules while parsing the information from the web site. For example if you expect a value to be a date then check that it’s really a date. This may greatly improve the quality of information. When you get unexpected data, then the algorithm need to be changed accordingly.

Respect Robots.txt

Robots.txt specifies the set of rules that should be followed by web crawlers and robots. I strongly advise you to consider and adjust your crawler to fully respect robots.txt. Robots.txt contains instructions on the exact pages that you are allowed to crawl, user-agent, and the requisite intervals between page requests. Following to these instructions minimizes the chance of getting blacklisted and banned from website owner.

Use XPath Smartly

XPath is a nice option to select elements of the HTML document more flexibly than CSS Selectors.  Be careful about HTML structure change through page to page so one xpath you made may be failed to extract data on another page due to changes in HTML structure.

Obey Website TOC:

Some websites make it absolutely apparent in their terms and conditions that they are particularly against to web scraping activities on their content. This can make you vulnerable against possible ethical and legal implications.

Test sample scrape and verify the data with actual scrape

Once you are done with web scraping project set up, you need to test it for sometimes. Check the extracted data. If something is not good, find out the cause and make changes accordingly and finally come to a perfect web scraping project.

Source: http://webdata-scraping.com/things-take-care-web-scraping/

How Web Scraping for Brand Monitoring is used in Retail Sector

How Web Scraping for Brand Monitoring is used in Retail Sector

Structured or unstructured, business data always plays an instrumental part in driving growth, development, and innovation for your dream venture. Irrespective of industrial sectors or verticals, big data, seems to be of paramount significance for every business or enterprise.

The unsurpassed popularity and increasing importance of big data gave birth to the concept of web scraping, thus enhancing growth opportunities for startups. Large or small, every business establishment will now achieve successful website monitoring and tracking.
How web scraping serves your branding need?

Web scraping helps in extracting unorganized data and ordering it into organized and manageable formats. So if your brand is being talked about in multiple ways (on social media, on expert forums, in comments etc.), you can set the scraping tool algorithm to fetch only data that contains reference about the brand. As an outcome, marketers and business owners around the brand can gauge brand sentiment and tweak their launch marketing campaign to enhance visibility.

Look around and you will discover numerous web scraping solutions ranging from manual to fully automated systems. From Reputation Tracking to Website monitoring, your web scraper can help create amazing insights from seemingly random bits of data (both in structured as well as unstructured format).
Using web scraping

The concept of web scraping revolutionizes the use of big data for business. With its availability across sectors, retailers are on cloud nine. Here’s how the retail market is utilizing the power of Web Scraping for brand monitoring.

Determining pricing strategy

The retail market is filled with competition. Whether it is products or pricing strategies, every retailer competes hard to stay ahead of the growth curve. Web scraping techniques will help you crawl price comparison sites’ pricing data, product descriptions, as well as images to receive data for comparison, affiliation, or analytics.

As a result, retailers will have the opportunity to trade their products at competitive prices, thus increasing profit margins by a whopping 10%.

Tracking online presence

Current trends in ecommerce herald the need for a strong online presence. Web scraping takes cue from this particular aspect, thus scraping reviews and profiles on websites. By providing you a crystal clear picture of product performance, customer behavior, and interactions, web scraping will help you achieve Online Brand Intelligence and monitoring.
Detection of fraudulent reviews

Present-day purchasers have this unique habit of referring to reviews, before finalizing their purchase decisions. Web scraping helps in the identification of opinion-spamming, thus figuring out fake reviews. It will further extend support in detecting, reviewing, streamlining, or blocking reviews, according to your business needs.
Online reputation management

Web data scraping helps in figuring out avenues to take your ORM objectives forward. With the help of the scraped data, you learn about both the impactful as well as vulnerable areas for online reputation management. You will have the web crawler identifying demographic opinions such as age group, gender, sentiments, and GEO location.

Social media analytics

Since social media happens to be one of the most crucial factors for retailers, it will be imperative to Scrape Social Media websites and extract data from Twitter. The web scraping technology will help you watch your brand in Social Media along with fetching Data for social media analytics. With social media channels such as Twitter monitoring services, you will strengthen your firm’s’ branding even more than before.
Advantages of BM

As a business, you might want to monitor your brand in social media to gain deep insights about your brand’s popularity and the current consumer behavior. Brand monitoring companies will watch your brand in social media and come up with crucial data for social media analytics. This process has immense benefits for your business, these are summarized over here –

Locate Infringers

Leading brands often face the challenge thrown by infringers. When brand monitoring companies keep a close look at products available in the market, there is less probability of a copyright infringement. The biggest infringement happens in the packaging, naming and presentation of products. With constant monitoring and legal support provided by the Trademark Law, businesses could remain protected from unethical competitors and illicit business practices.

Manage Consumer Reaction and Competitor’s Challenges

A good business keeps a check on the current consumer sentiment in the targeted demographic and positively manages the same in the interest of their brand. The feedback from your consumers could be affirmative or negative but if you have a hold on the social media channels, web platforms and forums, you, as a brand will be able to propagate trust at all times.

When competitor brands indulge in backbiting or false publicity about your brand, you can easily tame their negative comments by throwing in a positive image in front of your target audience. So, brand monitoring and its active implementation do help in positive image building and management for businesses.
Why Web scraping for BM?

Web scraping for brand monitoring gives you a second pair of eyes to look at your brand as a general consumer. Considering the flowing consumer sentiment in the market during a specific business season, you could correct or simply innovate better ways to mold the target audience in your brand’s favor. Through a systematic approach towards online brand intelligence and monitoring, future business strategies and possible brand responses could be designed, keeping your business actively prepared for both types of scenarios.

For effective web scraping, businesses extract data from Twitter that helps them understand ‘what’s trending’ in their business domain. They also come closer to reality in terms of brand perception, user interaction and brand visibility in the notions of their clientele. Web scraping professionals or companies scrape social media websites to gather relevant data related to your brand or your competitor’s that has the potential to affect your growth as a business. Management and organization of this data is done to extract out significant and reference building facts. Future strategy for your brand is designed by brand monitoring professionals keeping in mind the facts accumulated through web scraping. The data obtained through web scraping helps in –

Knowing the actual brand potential,
Expanding brand coverage,
Devising brand penetration,
Analyzing scope and possibilities for a brand and
Design thoughtful and insightful brand strategies.

In simple words, web scraping provides a business enough base of information that could be used to devise future plans and to make suggestive changes in the current business strategy.

Advantages of Web scraping for BM

Web scraping has made things seamless for businesses involved in managing their brands and active brand monitoring. There is no doubt, that web scraping for brand monitoring comes with immense benefits, some of these are –

Improved customer insight

When you have in hand and factual knowledge about your consumer base through social media channels, you are in a strong position to portray your positive image as a brand. With more realistic data on your hands, you could develop strategies more effectively and make realistic goals for your brand’s improvement. Social media insights also allows marketers to create highly targeted and custom marketing messages – thus leading to better likelihood of sales conversion.

Monitoring your Competition

Web scraping helps you realize where your brand stands in the market among the competition. The actual penetration of your brand in the targeted segment helps in getting a clear picture of your present business scenario. Through careful removal of competition in your concerned business category, you could strengthen your brand image.

Staying Informed

When your brand monitoring team is keeping track of all social media channels, it becomes easier for you to stay informed about latest comments about your business on sites like Facebook, Twitter and social forums etc. You could have deep knowledge about the consumer behavior related to your brand and your competitors on these web destinations.

Improved Consumer Satisfaction and Sales

Reputation tracking done through web scraping helps in generating planned response at times of crisis. It also mends the communication gap between consumer and the brand, hence improving the consumer satisfaction. This automatically translates into trust building and brand loyalty improving your brand’s sales.

To sign off

By granting opportunities to monitor your social media data, web scraping is undoubtedly helping retail businesses take a significant step towards perfect branding. If you are one of the key players in this sector, there’s reason for celebration ahead!

Source: https://www.promptcloud.com/blog/How-Web-Scraping-for-Brand-Monitoring-is-used-in-Retail-Sector