Screen-scraping with WWW::Mechanize

Screen-scraping is the process of emulating an interaction with a Web site - not just downloading pages, but filling out forms, navigating around the site, and dealing with the HTML received as a result. As well as for traditional lookups of information - like the example we'll be exploring in this article - we can use screen-scraping to enhance a Web service into doing something the designers hadn't given us the power to do in the first place. Here's an example:

I do my banking online, but get quickly bored with having to go to my bank's site, log in, navigate around to my accounts and check the balance on each of them. One quick Perl module (Finance::Bank::HSBC) later, and now I can loop through each of my accounts and print their balances, all from a shell prompt. Some more code, and I can do something the bank's site doesn't ordinarily let me - I can treat my accounts as a whole instead of individual accounts, and find out how much money I have, could possibly spend, and owe, all in total.

Another step forward would be to schedule a crontab every day to use the HSBC option to download a copy of my transactions in Quicken's QIF format, and use Simon Cozens' Finance::QIF module to interpret the file and run those transactions against a budget, letting me know whether I'm spending too much lately. This takes a simple Web-based system from being merely useful to being automated and bespoke; if you can think of how to write the code, then you can do it. (It's probably wise for me to add the caveat, though, that you should be extremely careful working with banking information programatically, and even more careful if you're storing your login details in a Perl script somewhere.)

Back to screen-scrapers, and introducing WWW::Mechanize, written by Andy Lester and based on Skud's WWW::Automate. Mechanize allows you to go to a URL and explore the site, following links by name, taking cookies, filling in forms and clicking "submit" buttons. We're also going to use HTML::TokeParser to process the HTML we're given back, which is a process I've written about previously.

The site I've chosen to demonstrate on is the BBC's Radio Times site, which allows users to create a "Diary" for their favorite TV programs, and will tell you whenever any of the programs is showing on any channel. Being a London Perl M[ou]nger, I have an obsession with Buffy the Vampire Slayer. If I tell this to the BBC's site, then it'll tell me when the next episode is, and what the episode name is - so I can check whether it's one I've seen before. I'd have to remember to log into their site every few days to check whether there was a new episode coming along, though. Perl to the rescue! Our script will check to see when the next episode is and let us know, along with the name of the episode being shown.

Here's the code:

  #!/usr/bin/perl -w
  use strict;
  use WWW::Mechanize;
  use HTML::TokeParser;

If you're going to run the script yourself, then you should register with the Radio Times site and create a diary, before giving the e-mail address you used to do so below.

  my $email = ";
  die "Must provide an e-mail address" unless $email ne ";

We create a WWW::Mechanize object, and tell it the address of the site we'll be working from. The Radio Times' front page has an image link with an ALT text of "My Diary", so we can use that to get to the right section of the site:

  my $agent = WWW::Mechanize->new();
  $agent->get("http://www.radiotimes.beeb.com/");
  $agent->follow("My Diary");

The returned page contains two forms - one to allow you to choose from a list box of program types, and then a login form for the diary function. We tell WWW::Mechanize to use the second form for input. (Something to remember here is that WWW::Mechanize's list of forms, unlike an array in Perl, is indexed starting at 1 rather than 0. Our index is, therefore,'2.')

  $agent->form(2);

Now we can fill in our e-mail address for the '<INPUT name="email" type="text">' field, and click the submit button. Nothing too complicated.

  $agent->field("email", $email);
  $agent->click();

WWW::Mechanize moves us to our diary page. This is the page we need to process to find the date details from. Upon looking at the HTML source for this page, we can see that the HTML we need to work through is something like:

  <input>
  <tr><td></td></tr>
  <tr><td></td><td></td><td class="bluetext">Date of episode</td></tr>
  <td></td><td></td>
  <td class="bluetext"><b>Time of episode</b></td></tr>
  <a href="page_with_episode_info"></a>

This can be modeled with HTML::TokeParser as below. The important methods to note are get_tag - which will move the stream on to the next opening for the tag given - and get_trimmed_text, which returns the text between the current and given tags. For example, for the HTML code "<b>Bold text here</b>", my $tag = get_trimmed_text("/b") would return "Bold text here" to $tag.

Also note that we're initializing HTML::TokeParser on '\$agent->{content}' - this is an internal variable for WWW::Mechanize, exposing the HTML content of the current page.

  my $stream = HTML::TokeParser->new(\$agent->{content});
  my $date;
    # <input>
  $stream->get_tag("input");
  # <tr><td></td></tr><tr>
  $stream->get_tag("tr"); $stream->get_tag("tr");
  # <td></td><td></td>
  $stream->get_tag("td"); $stream->get_tag("td");
  # <td class="bluetext">Date of episode</td></tr>
  my $tag = $stream->get_tag("td");
  if ($tag->[1]{class} and $tag->[1]{class} eq "bluetext") {
      $date = $stream->get_trimmed_text("/td");
      # The date contains '&nbsp;', which we'll translate to a space.
      $date =~ s/\xa0/ /g;
  }
   # <td></td><td></td>
  $stream->get_tag("td");
  # <td class="bluetext"><b>Time of episode</b> 
  $tag = $stream->get_tag("td");
  if ($tag->[1]{class} eq "bluetext") {
      $stream->get_tag("b");
      # This concatenates the time of the showing to the date.
      $date .= ", from " . $stream->get_trimmed_text("/b");
  }
  # </td></tr><a href="page_with_episode_info"></a>
  $tag = $stream->get_tag("a");
  # Match the URL to find the page giving episode information.
  $tag->[1]{href} =~ m!src=(http://.*?)'!;

We have a scalar, $date, containing a string that looks something like "Thursday 23 January, from 6:45pm to 7:30pm.", and we have an URL, in $1, that will tell us more about that episode. We tell WWW::Mechanize to go to the URL:

  $agent->get($1);

The navigation we want to perform on this page is far less complex than on the last page, so we can avoid using a TokeParser for it - a regular expression should suffice. The HTML we want to parse looks something like this:

  <br><b>Episode</b><br>  The Episode Title<br>

We use a regex delimited with '!' in order to avoid having to escape the slashes present in the HTML, and store any number of alphanumeric characters after some whitespace, all between <br> tags after the Episode header:

  $agent->{content} =~ m!<br><b>Episode</b><br>\s+?(\w+?)<br>!;

$1 now contains our episode, and all that's left to do is print out what we've found:

  my $episode = $1;
  print "The next Buffy episode ($episode) is on $date.\n";

And we're all set. We can run our script from the shell:

  $ perl radiotimes.pl

  The next Buffy episode (Gone) is Thursday Jan. 23, from 6:45 to 7:30 p.m.
I hope this gives a light-hearted introduction to the usefulness of the modules involved. As a note for your own experiments, WWW::Mechanize supports cookies - in that the requestor is a normal LWP::UserAgent object - but they aren't enabled by default. If you need to support cookies, then your script should call "use HTTP::Cookies; $agent->cookie_jar(HTTP::Cookies->new);" on your agent object in order to enable session-volatile cookies for your own code.
Happy screen-scraping, and may you never miss a Buffy episode again.

Source: http://www.perl.com/pub/2003/01/22/mechanize.html

Why Businesses Need Data Scraping Service?

With the ever-increasing popularity of internet technology there is an abundance of knowledge processing information that can be used as gold if used in a structured format. We all know the importance of information. It has indeed become a valuable commodity and most sought after product for businesses. With widespread competition in businesses there is always a need to strive for better performances.

Taking this into consideration web data scraping service has become an inevitable component of businesses as it is highly useful in getting relevant information which is accurate. In the initial periods data scraping process included copying and pasting data information which was not relevant because it required intensive labor and was very costly. But now with the help of new data scraping tools like Mozenda, it is possible to extract data from websites easily. You can also take the help of data scrapers and data mining experts that scrape the data and automatically keep record of it.

How Professional Data Scraping Companies and Data Mining Experts Device a Solution?

Data Scraping Plan and Solutions

ImageCredit:http://www.loginworks.com/images/newscapingpage/data-as-service-plan.png

Why Data Scraping is Highly Essential for Businesses?

Data scraping is highly essential for every industry especially Hospitality, eCommerce, Research and Development, Healthcare, Financial and data scraping can be useful in marketing industry, real estate industry by scraping properties, agents, sites etc., travel and tourism industry etc. The reason for that is it is one of those industries where there is cut-throat competition and with the help of data scraping tools it is possible to extract useful information pertaining to preferences of customers, their preferred location, strategies of your competitors etc.

It is very important in today’s dynamic business world to understand the requirements of your customers and their preferences. This is because customers are the king of the market they determine the demand. Web data scraping process will help you in getting this vital information. It will help you in making crucial decisions which are highly critical for the success of business. With the help of data scraping tools you can automate the data scraping process which can result in increased productivity and accuracy.

Reasons Why Businesses Opt. For Website Data Scraping Solutions:

Website Scraping
Demand For New Data:

There is an overflowing demand for new data for businesses across the globe. This is due to increase in competition. The more information you have about your products, competitors, market etc. the better are your chances of expanding and persisting in competitive business environment. The manner in which data extraction process is followed is also very important; as mere data collection is useless. Today there is a need for a process through which you can utilize the information for the betterment of the business. This is where data scraping process and data scraping tools come into picture.

ImageCredit:3idatascraping.com
Capitalize On Hot Updates:

Today simple data collection is not enough to sustain in the business world. There is a need for getting up to date information. There are times when you will have the information pertaining to the trends in the market for your business but they would not be updated. During such times you will lose out on critical information. Hence; today in businesses it is a must to have recent information at your disposal.

The more recent update you have pertaining to the services of your business the better it is for your growth and sustenance. We are already seeing lot of innovation happening in the field of businesses hence; it is very important to be on your toes and collect relevant information with the help of data scrapers. With the help of data scrapping tools you can stay abreast with the latest developments in your business albeit; by spending extra money but it is necessary tradeoff in order to grow in your business or be left behind like a laggard.

Analyzing Future Demands:

Foreknowledge about the various major and minor issues of your industry will help you in assessing the future demand of your product / service. With the help of data scraping process; data scrapers can gather information pertaining to possibilities in business or venture you are involved in. You can also remain alert for changes, adjustments, and analysis of all aspects of your products and services.

Appraising Business:

It is very important to regularly analyze and evaluate your businesses. For that you need to evaluate whether the business goals have been met or not. It is important for businesses to know about your own performance. For example; for your businesses if the world market decides to lower the prices in order to grow their customer base you need to be prepared whether you can remain in the industry despite lowering the price. This can be done only with the help of data scraping process and data scraping tools.

Source:http://www.habiledata.com/blog/why-businesses-need-data-scraping-service

Example of Scraping with Selenium WebDriver in C#

In this article I will show you how it is easy to scrape a web site using Selenium WebDriver. I will guide you through a sample project which is written in C# and uses WebDriver in conjunction with the Chrome browser to login on the testing page and scrape the text from the private area of the website.

Downloading the WebDriver

First of all we need to get the latest version of Selenium Client & WebDriver Language Bindings and the Chrome Driver. Of course, you can download WebDriver bindings for any language (Java, C#, Python, Ruby), but within the scope of this sample project I will use the C# binding only. In the same manner, you can use any browser driver, but here I will use Chrome.

After downloading the libraries and the browser driver we need to include them in our Visual

Studio solution:

VS Solution

Creating the scraping program

In order to use the WebDriver in our program we need to add its namespaces:

using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;

Then, in the main function, we need to initialize the Chrome Driver:

using (var driver = new ChromeDriver())

{

 This piece of code searches for the chromedriver.exe file. If this file is located in a directory different from the directory where our program is executed, then we need to specify explicitly its path in the ChromeDriver constructor.

When an instance of ChromeDriver is created, a new Chrome browser will be started. Now we can control this browser via the driver variable. Let’s navigate to the target URL first:

driver.Navigate().GoToUrl("http://testing-ground.scraping.pro/login");

Then we can find the web page elements needed for us to login in the private area of the website:

var userNameField = driver.FindElementById("usr");
var userPasswordField = driver.FindElementById("pwd");
var loginButton = driver.FindElementByXPath("//input[@value='Login']");

Here we search for user name and password fields and the login button and put them into the corresponding variables. After we have found them, we can type in the user name and the password  and press the login button:

userNameField.SendKeys("admin");
userPasswordField.SendKeys("12345");
loginButton.Click();

At this point the new page will be loaded into the browser, and after it’s done we can scrape the text we need and save it into the file:

var result = driver.FindElementByXPath("//div[@id='case_login']/h3").Text;

File.WriteAllText("result.txt", result);

That’s it! At the end, I’d like to give you a bonus – saving a screenshot of the current page into a file:

driver.GetScreenshot().SaveAsFile(@"screen.png", ImageFormat.Png);

The complete program listing

using System.IO;
using System.Text;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;

namespace WebDriverTest
{
    class Program
    {
        static void Main(string[] args)
        {
            // Initialize the Chrome Driver
            using (var driver = new ChromeDriver())
            {
                // Go to the home page
                driver.Navigate().GoToUrl("http://testing-ground.scraping.pro/login");

                // Get the page elements
                var userNameField = driver.FindElementById("usr");
                var userPasswordField = driver.FindElementById("pwd");
                var loginButton = driver.FindElementByXPath("//input[@value='Login']");

                // Type user name and password
                userNameField.SendKeys("admin");
                userPasswordField.SendKeys("12345");

                // and click the login button
                loginButton.Click();

                // Extract the text and save it into result.txt
                var result = driver.FindElementByXPath("//div[@id='case_login']/h3").Text;
                File.WriteAllText("result.txt", result);

                // Take a screenshot and save it into screen.png
                driver.GetScreenshot().SaveAsFile(@"screen.png", ImageFormat.Png);
            }
        }
    }
}

Also you can download a ready project here.

Conclusion

I hope you are impressed with how easy it is to scrape web pages using the WebDriver. You can naturally press keys and click buttons as you would in working with the browser. You don’t even need to understand what kind of HTTP requests are sent and what cookies are stored; the browser does all this for you. This makes the WebDriver a wonderful tool in the hands of a web scraping specialist.

Source:http://scraping.pro/example-of-scraping-with-selenium-webdriver-in-csharp/

Web Scraping: Business Intelligence

Web scraping is simply getting of information that is both hidden and unhidden from the internet. Web scraping is one of the latest technologies used in harvesting data from WebPages. It has been used to extract useful information for practical and beneficial applications and its interpretation has been tested in decision making. Web scraping is a new term that overshadows the traditional data harvesting technique that was used before. It has been regarded as knowledge discovery in databases for research and even marketing monitoring.

This article explores the various business intelligence ways in which web scraping can be used to be of importance.

Web scraping services has been used by many companies that have a strong customer focus. These companies range from sectors like retail, financial services, and marketing and communication organizations. It quite important to realize that web scraping has great signifies and impact in the varied commercial applications for the better understanding and prediction of the critical data. The data may range from stocks to consumer behaviors. The consumer behaviors are better shown in trends like customer profiles, purchasing and industry analysis among others.

Source:http://www.loginworks.com/blogs/web-scraping-blogs/web-scraping-business-intelligence/

Web Scraping Popularity Soars

The world is stirred because of the ever-growing web scraping success in almost all of its services. Success stories pertaining to the benefits of online data collection in business, research, politics, health, and almost all aspects of human life are endless. With this popularity surge, it has become a hot issue and many are questioning its legality and reliability.

Looking back, this simple harvesting of pertinent data from competitors and the global market in general like anything else started as a non-threatening and advanced form of web research. Eventually, when the benefits begin to manifest and the system improves, many are lured into it that it has become one of the strongest and fastest growing business in the world.

Simple Beginnings

As naturally as a law of life that great things come from small beginnings, data mining was conceived as a process in gaining information, mostly in research. This act of collecting information through the internet was never imagined to be what it has become nowadays.

Source:http://www.loginworks.com/blogs/web-scraping-blogs/web-scraping-popularity-soars/

Scraping webdata from a website that loads data in a streaming fashion

I'm trying to scrape some data off of the FEC.gov website using python for a project of mine. Normally I use python

mechanize and beautifulsoup to do the scraping.

I've been able to figure out most of the issues but can't seem to get around a problem. It seems like the data is

streamed into the table and mechanize.Browser() just stops listening.

So here's the issue: If you visit http://query.nictusa.com/cgi-bin/can_ind/2011_P80003338/1/A ... you get the first 500

contributors whose last name starts with A and have given money to candidate P80003338 ... however, if you use

browser.open() at that url all you get is the first ~5 rows.

I'm guessing its because mechanize isn't letting the page fully load before the .read() is executed. I tried putting a

time.sleep(10) between the .open() and .read() but that didn't make much difference.

And I checked, there's no javascript or AJAX in the website (or at least none are visible when you use the 'view-

source'). SO I don't think its a javascript issue.

Any thoughts or suggestions? I could use selenium or something similar but that's something that I'm trying to avoid.

-Will

2 Answers

Why not use an html parser like lxml with xpath expressions.

I tried

>>> import lxml.html as lh
>>> data = lh.parse('http://query.nictusa.com/cgi-bin/can_ind/2011_P80003338/1/A')
>>> name = data.xpath('/html/body/table[2]/tr[5]/td[1]/a/text()')
>>> name
[' AABY, TRYGVE']
>>> name = data.xpath('//table[2]/*/td[1]/a/text()')
>>> len(name)
500
>>> name[499]
' AHMED, ASHFAQ'
>>>



Similarly, you can create xpath expression of your choice to work with.


Source: http://stackoverflow.com/questions/9435512/scraping-webdata-from-a-website-that-loads-data-in-a-streaming-

fashion

How can I circumvent page view limits when scraping web data using Python?

I am using Python to scrape US postal code population data from http:/www.city-data.com, through this directory: http://www.city-data.com/zipDir.html. The specific pages I am trying to scrape are individual postal code pages with URLs like this: http://www.city-data.com/zips/01001.html. All of the individual zip code pages I need to access have this same URL Format, so my script simply does the following for postal_code in range:

    Creates URL given postal code
    Tries to get response from URL
    If (2), Check the HTTP of that URL
    If HTTP is 200, retrieves the HTML and scrapes the data into a list
    If HTTP is not 200, pass and count error (not a valid postal code/URL)
    If no response from URL because of error, pass that postal code and count error
    At end of script, print counter variables and timestamp

The problem is that I run the script and it works fine for ~500 postal codes, then suddenly stops working and returns repeated timeout errors. My suspicion is that the site's server is limiting the page views coming from my IP address, preventing me from completing the amount of scraping that I need to do (all 100,000 potential postal codes).

My question is as follows: Is there a way to confuse the site's server, for example using a proxy of some kind, so that it will not limit my page views and I can scrape all of the data I need?

Thanks for the help! Here is the code:

##POSTAL CODE POPULATION SCRAPER##

import requests

import re

import datetime

def zip_population_scrape():

    """
    This script will scrape population data for postal codes in range
    from city-data.com.
    """
    postal_code_data = [['zip','population']] #list for storing scraped data

    #Counters for keeping track:
    total_scraped = 0
    total_invalid = 0
    errors = 0


    for postal_code in range(1001,5000):

        #This if statement is necessary because the postal code can't start
        #with 0 in order for the for statement to interate successfully
        if postal_code <10000:
            postal_code_string = str(0)+str(postal_code)
        else:
            postal_code_string = str(postal_code)

        #all postal code URLs have the same format on this site
        url = 'http://www.city-data.com/zips/' + postal_code_string + '.html'

        #try to get current URL
        try:
            response = requests.get(url, timeout = 5)
            http = response.status_code

            #print current for logging purposes
            print url +" - HTTP:  " + str(http)

            #if valid webpage:
            if http == 200:

                #save html as text
                html = response.text

                #extra print statement for status updates
                print "HTML ready"

                #try to find two substrings in HTML text
                #add the substring in between them to list w/ postal code
                try:           

                    found = re.search('population in 2011:</b> (.*)<br>', html).group(1)

                    #add to # scraped counter
                    total_scraped +=1

                    postal_code_data.append([postal_code_string,found])

                    #print statement for logging
                    print postal_code_string + ": " + str(found) + ". Data scrape successful. " + str(total_scraped) + " total zips scraped."
                #if substrings not found, try searching for others
                #and doing the same as above   
                except AttributeError:
                    found = re.search('population in 2010:</b> (.*)<br>', html).group(1)

                    total_scraped +=1

                    postal_code_data.append([postal_code_string,found])
                    print postal_code_string + ": " + str(found) + ". Data scrape successful. " + str(total_scraped) + " total zips scraped."

            #if http =404, zip is not valid. Add to counter and print log        
            elif http == 404:
                total_invalid +=1

                print postal_code_string + ": Not a valid zip code. " + str(total_invalid) + " total invalid zips."

            #other http codes: add to error counter and print log
            else:
                errors +=1

                print postal_code_string + ": HTTP Code Error. " + str(errors) + " total errors."

        #if get url fails by connnection error, add to error count & pass
        except requests.exceptions.ConnectionError:
            errors +=1
            print postal_code_string + ": Connection Error. " + str(errors) + " total errors."
            pass

        #if get url fails by timeout error, add to error count & pass
        except requests.exceptions.Timeout:
            errors +=1
            print postal_code_string + ": Timeout Error. " + str(errors) + " total errors."
            pass


    #print final log/counter data, along with timestamp finished
    now= datetime.datetime.now()
    print now.strftime("%Y-%m-%d %H:%M")
    print str(total_scraped) + " total zips scraped."
    print str(total_invalid) + " total unavailable zips."
    print str(errors) + " total errors."



Source: http://stackoverflow.com/questions/25452798/how-can-i-circumvent-page-view-limits-when-scraping-web-data-using-python