Tuesday, 30 December 2014

Web Data Scraping Services At Lowest Rate For Business Directory

We are the world's most trusted provider directory, your business data scrape, and scrape email scraping and sending the data needed. We scour the entire directory database or doctors, lawyers, brokers, financial advisers, etc. As the scraping of a particular industry category wise database scraping or data that can be adapted.

We are pioneers in the worldwide web scraping and data services. We must understand the value of our customer database, we email id with the greatest effort to collect data. We are lawyers, doctors, brokers, realtors, schools, students, universities, IT managers, pubs, bars, nightclubs, dance clubs, financial advisers, liquor stores, Face book, Twitter, pharmaceutical companies, mortgage broker scraped data, accounting firms, car dealers , artists, shop health and job portals.

Our business database development services to try and get real quality at the lowest possible industry. Example worked. We have a quick turnaround time can be a business mailing database. Our business database development services to try and get real quality at the lowest possible industry. Example worked. We have a quick turnaround time can be a business mailing database.

We are the world's most trusted provider directory, your business data scrape, and scrape email scraping and sending the data needed. We scour the entire directory database or doctors, lawyers, brokers, financial advisers, etc., as the scraping of a particular industry category wise database scraping or data that can be adapted.

We are pioneers in the worldwide web scraping and data services. We must understand the value of our customer database, we email id with the greatest effort to collect data. We are lawyers, doctors, brokers, realtors, schools, students, universities, IT managers, pubs, bars, nightclubs, dance clubs, financial advisers, liquor stores, Face book, Twitter, pharmaceutical companies, mortgage broker scraped data, accounting firms, car dealers , artists, shop health and job portals.

What a great resource for specific information or content with little success to gather and have tried to organize themselves in a folder? You no longer need to worry, and data processing services through our website search are the best solution for your problem.

We currently have an "information explosion" phase of the walk, where there is so much information and content information for an event or a small group of channels.

Order without the benefit of you and your customers a little truth to that information. You use information and material is easy to organize in a way that is needed. Something other than a small business guide, simply create a separate folder in less than an hour.

Our technology-specific Web database for you to a similar configuration and database development to use. In addition, we finished our services can help you through the data to identify the sources of information for web pages to follow. This is a cost effective way to create a database.

We offer directory database, company name, address, the state, country, phone, email and website URL to take. In recent projects we have completed. We have a quick turnaround time can be a business mailing database. Our business database development services to try and get real quality at the lowest possible industry.

Source:http://www.articlesbase.com/outsourcing-articles/web-data-scraping-services-at-lowest-rate-for-business-directory-5757029.html

Sunday, 28 December 2014

What Kind of Legal Problems Can Web Scraping Cause

Web scraping software is readily available and has been used by many for legitimate purposes. It has also been used for illegal purposes. A website that engages in this practice should know the legal dangers of the activity.

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Black Hat SEO Popular Techniques

General Knowledge- VII

The idea of web scraping is not new. Search engines have used this type of software to determine which results appear when someone conducts a search. They use special software software to extract data from a website and this data is then used to calculate the rankings of the website. Websites work very hard to improve their ranking and their chance of being found by anyone making a search. This use of this practice is understood and is considered to be a legitimate use for the software. However, there are services that provide web scraping and screen scraping prevention services and help the webmaster to remain safe from the attack of bad bots.

The problem with duplicacy is that it is often used for less than legitimate reasons. Since the software responsible can collect all sorts of data from websites and store the information that is collected, it represents a danger to anyone who might be affected by it. The information that can be collected can be used for many practices that are not so legitimate and may even be illegal. Anyone who is involved in this practice of content duplicacy should be aware of the legal issues implicated with this practice. It may be wise for anyone who has a website to find ways to prevent a site from being scraped or to use professional services to block site scraping.

Legal problems

The first thing to worry about, if you have a website or are using web scraping software, is when you might run into legal problems. Some of the issues that web scraping can cause include:

•    Access. If the software is used to access sites it does not have the right to access and takes information that it is not entitled to, the owner of the web scarping software may find themselves in legal trouble.

•    Re-use. The software can collect and reuse information. If that information is copyrighted, that might be a legal problem. Any information that is reused without permission may create legal issues for anyone who uses it.

•    Robots. Some states have enacted laws that are designed to keep people from using scraping robots. These automatically search out information on websites and using them may be illegal in some states. It is up to the user of the web scraping software to comply with any laws in the state in which they are operating.

Who is Responsible

The laws and regulations surrounding this practice are not always clear. There are many grey areas that allow this practice to occur. The question is, who is responsible for determining whether the use of web scraping software is legal?

Websites collect the information, but they may not be the entity using the web scraping software. If they are using this type of software, it is not always enough to inform the website's visitors that this practice is occurring. Putting this information into the user agreement may or may not protect the website from legal problems.

It is also partly the responsibility of a site owner to prevent a site from being scraped. There is software that can be used that will do this for a website and will keep any information that is collected safe and secure. A website may or may not be held legally responsible for any web scraper that is able to collect information they have. It will depend on why the data was collected, how it was used, who collected it, and whether precautions were taken.

What to expect

The issue of content copying and the legal issues surrounding it will continue to evolve. As more courts take on this issue, the lines between legal and illegal web scraping will become clearer. Many of the cases that have been brought to court have occurred in civil court, although there are some that have been taken up in a criminal court. There will be times when such practice may actually be a felony.

Before you use spying software, you need to realize that the laws surrounding its use are not clear. If you operate a website, you need to know the legal issues that you may face if scraping software is used on your website. The best step is to use the software available to protect your website and stop web scraping and be honest on your site if web scraping is used.

Source: http://www.articlesbase.com/technology-articles/what-kind-of-legal-problems-can-web-scraping-cause-6780486.html

Thursday, 25 December 2014

Central Qld Coal: Mining for Needed Investments

The Central Qld Coal Project is situated in the Galilee Coal Basin, Central Queensland with the purpose of establishing a mine to service international export markets for thermal coal. An estimated cost to such a project would be around $ 7.5 billion - the amount proves that the mining industry is one serious business to begin with.

In addition to the mine, the Central Qld Coal Project also proposes to construct a railway, potentially in excess of 400km depending on the final option: Either to transport processed coal to an expanded facility at Abbot Point or new export terminal to be established at Dudgeon Point. However, this would require new major water and power supply infrastructure to service the mine and port - hence, the extremely high cost. Because mining areas usually involve desolate areas where there is no direct risk to developed regions where the populace thrives, setting up new major water and power supplies would simply demand costs as high as the estimated cost - but this is not the only major percent of the whole budget of the Central Qld Coal Project.

The location for the Central Qld Coal Project is situated 40km northwest of Alpha, approximately 450 km west of Rockhampton and contains an amount of more than three billion tons. The proposed open-cut mine of the Central Qld Coal Project is expected to be developed in stages. It shall have an initial export capacity of 30 million tons per annum with a mine life expectancy of 30 years.

In terms of employment regarding Central Qld Coal Project, there will be around a total of 2,500 people to be employed during the construction and 1,600 permanent positions shall be employed in the operation stage of the Central Qld Coal Project.

Australia is a major coal exporter - the largest exporter of coal and fourth largest producer of coal. Australia is also the second largest producer of gold, second only to China. As for Opal, Australia is responsible for 95% of its production, thereby making her the largest producer worldwide. Australia would not also lose in terms of commercially viable diamond deposits - being third next after Russia and Botswana. This pretty much explains the significance of the mining industry to Australia. It is like the backbone of its economy; an industry focused on claiming the blessings the earth has giver her lands. The Central Qld Coal Project was made to further the exports and improve the trade. However, the Central Qld Coal Project requires quite a large sum for its project. It is only through the financial support of investments, both local and international, can it achieve its goals and begin reaping the fruits of the land.

Source: http://ezinearticles.com/?Central-Qld-Coal:-Mining-for-Needed-Investments&id=6314576

Monday, 22 December 2014

GScholarXScraper: Hacking the GScholarScraper function with XPath

Kay Cichini recently wrote a word-cloud R function called GScholarScraper on his blog which when given a search string will scrape the associated search results returned by Google Scholar, across pages, and then produce a word-cloud visualisation.

This was of interest to me because around the same time I posted an independent Google Scholar scraper function  get_google_scholar_df() which does a similar job of the scraping part of Kay’s function using XPath (whereas he had used Regular Expressions). My function worked as follows: when given a Google Scholar URL it will extract as much information as it can from each search result on the URL webpage  into different columns of a dataframe structure.

In the comments of his blog post I figured it’d be fun to hack his function to provide an XPath alternative, GScholarXScraper. Essensially it’s still the same function he wrote and therefore full credit should go to Kay on this one as he fully deserves it – I certainly had no previous idea how to make a word cloud, plus I hadn’t used the tm package in ages (to the point where I’d forgotten most of it!). The main changes I made were as follows:

    Restructure internal code of GScholarScraper into a series of local functions which each do a seperate job (this made it easier for me to hack because I understood what was doing what and why).

    As far as possible, strip out Regular Expressions and replace with XPath alternatives (made possible via the XML package). Hence the change of name to GScholarXScraper. Basically, apart from a little messing about with the generation of the URLs I just copied over my get_google_scholar_df() function and removed the Regular Expression alternatives. I’m not saying one is better than the other but f0r me personally, I find XPath shorter and quicker to code but either is a good approach for web scraping like this (note to self: I really need to lean more about regular expressions!) :)

•    Vectorise a few of the loops I saw (it surprises me how second nature this has become to me – I used to find the *apply family of functions rather confusing but thankfully not so much any more!).
•    Make use of getURL from the RCurl package (I was getting some mutibyte string problems originally when using readLines but this approach automatically fixed it for me).
•    Add option to make a word-cloud from either the “title” or the “description” fields of the Google Scholar search results
•    Added steaming via the Rstem package because I couldn’t get the Snowball package to install with my version of java. This was important to me because I was getting word clouds with variations of the same word on it e.g. “game”, “games”, “gaming”.
•    Forced use of URLencode() on generation of URLs to automatically avoid problems with search terms like “Baldur’s Gate” which would otherwise fail.

I think that’s pretty much everything I added. Anyway, here’s how it works (link to full code at end of post):

</pre>
<div id="LC198"># #EXAMPLE 1: Display word cloud based on the title field of each Google Scholar search result returned</div>
<div id="LC199"># GScholarXScraper(search.str = "Baldur's Gate", field = "title", write.table = FALSE, stem = TRUE)</div>
<div id="LC200">#</div>
<div id="LC201"># # word freq</div>
<div id="LC202"># # game game 71</div>
<div id="LC203"># # comput comput 22</div>
<div id="LC204"># # video video 13</div>
<div id="LC205"># # learn learn 11</div>
<div id="LC206"># # [TRUNC...]</div>
<div id="LC207"># #</div>
<div id="LC208"># #</div>
<div id="LC209"># # Number of titles submitted = 210</div>
<div id="LC210"># #</div>
<div id="LC211"># # Number of results as retrieved from first webpage = 267</div>
<div id="LC212"># #</div>
<div id="LC213"># # Be aware that sometimes titles in Google Scholar outputs are truncated - that is why, i.e., some mandatory intitle-search strings may not be contained in all titles</div>

<pre>

// image

I think that’s kind of cool and corresponds to what I would expect for a search about the legendary Baldur’s Gate computer role playing game :)  The following is produced if we look at the ‘description’ filed instead of the ‘title’ field:

</pre>

<div id="LC215"># # EXAMPLE 2: Display word cloud based on the description field of each Google Scholar search result returned</div>
<div id="LC216">GScholarXScraper(search.str = "Baldur's Gate", field = "description", write.table = FALSE, stem = TRUE)</div>
<div id="LC217">#</div>
<div id="LC218"># # word freq</div>
<div id="LC219"># # page page 147</div>
<div id="LC220"># # gate gate 132</div>
<div id="LC221"># # game game 130</div>
<div id="LC222"># # baldur baldur 129</div>
<div id="LC223"># # roleplay roleplay 21</div>
<div id="LC224"># # [TRUNC...]</div>
<div id="LC225"># #</div>
<div id="LC226"># # Number of titles submitted = 210</div>
<div id="LC227"># #</div>
<div id="LC228"># # Number of results as retrieved from first webpage = 267</div>
<div id="LC229"># #</div>
<div id="LC230"># # Be aware that sometimes titles in Google Scholar outputs are truncated - that is why, i.e., some mandatory intitle-search strings may not be contained in all titles</div>
<pre>

//image

Not bad. I could see myself using the text mining and word cloud functionality with other projects I’ve been playing with such as Facebook, Google+, Yahoo search pages, Google search pages, Bing search pages… could be fun!

Many thanks again to Kay for making his code publicly available so that I could play with it and improve my programming skill set.

Code:

Full code for GScholarXScraper can be found here: https://github.com/tonybreyal/Blog-Reference-Functions/blob/master/R/GScholarXScraper/GScholarXScraper

Original GSchloarScraper code is here: https://docs.google.com/document/d/1w_7niLqTUT0hmLxMfPEB7pGiA6MXoZBy6qPsKsEe_O0/edit?hl=en_US

Full code for just the XPath scraping function is here: https://github.com/tonybreyal/Blog-Reference-Functions/blob/master/R/googleScholarXScraper/googleScholarXScraper.R

Source:http://www.r-bloggers.com/gscholarxscraper-hacking-the-gscholarscraper-function-with-xpath/

Wednesday, 17 December 2014

Online Data Entry and Data Mining Services

Data entry job involves transcribing a particular type of data into some other form. It can be either online or offline. The input data may include printed documents like Application forms, survey forms, registration forms, handwritten documents etc.

Data entry process is an inevitable part of the job to any organization. One way or other each organization demands data entry. Data entry skills vary depends upon the nature of the job requirement, in some cases data to be entered from a hard copy formats and in some other cases data to be entered directly into a web portal. Online data entry job generally requires the data to be entered in to any online data base.

For a super market, data associate might be required to enter the goods which have sold in a particular day and the new goods received in a particular day to maintain the stock well in order. Also, by doing this the concerned authorities will get an idea about the sale particulars of each commodity as they requires. In another example, an office the account executive might be required to input the day to day expenses in to the online accounting database in order to keep the account well in order.

The aim of the data mining process is to collect the information from reliable online sources as per the requirement of the customer and convert it to a structured format for the further use. The major source of data mining is any of the internet search engine like Google, Yahoo, Bing, AOL, MSN etc. Many search engines such as Google and Bing provide customized results based on the user's activity history. Based on our keyword search, the search engine lists the details of the websites from where we can gather the details as per our requirement.

Collect the data from the online sources such as Company Name, Contact Person, Profile of the Company, Contact Phone Number of Email ID Etc. are doing for the marketing activities. Once the data is gathered from the online sources into a structured format, the marketing authorities will start their marketing promotions by calling or emailing the concerned persons, which may result to create a new customer. So basically data mining is playing a vital role in today's business expansions. By outsourcing the data entry and its related works, you can save the cost that would be incurred in setting up the necessary infrastructure and employee cost.

Source:http://ezinearticles.com/?Online-Data-Entry-and-Data-Mining-Services&id=7713395

Monday, 15 December 2014

Git workflow for Scrapy projects

Our customers often ask us what’s the best workflow for working with Scrapy projects. A popular approach we have seen and used in the past is to split the spiders folder (typically project/spiders) into two folders: project/spiders_prod and project/spiders_dev, and use the SPIDER_MODULES setting to control which spiders are loaded on each environment. This works reasonably well, until you have to make changes to common code used by many spiders (ie. code outside the spiders folder), for example common base spiders.

Nowadays, DVCS (in particular, git) have become more popular and people are quite used to branching, so we recommend using a simple git workflow (similar to GitHub flow) where you branch for every change you make. You keep all changes in a branch while they’re being tested and finally merge to master when they’re finished. This means that master branch is always stable and contains only “production-ready” spiders.

If you are using our Scrapy Cloud platform, you can have 2 projects (myproject-dev, myproject-prod) and use myproject-dev to test the changes in your branch.  scrapy deploy in Scrapy 0.17 now adds the branch name to the version name (when using version=GIT or version=HG), so you can see which branch you are going to run directly on the panel. This is particularly useful with large teams working on a single Scrapy project, to avoid stepping into each other when making changes to common code.

Here is a concrete example to illustrate how this workflow works:y

•    the developer decides to work on issue 123 (could be a new spider or fixes to an existing spider)
•    the developer creates a new branch to work on the issue
•    git checkout -b issue123
•    the developer finishes working on the code and deploys to the panel (this assumes scrapy.cfg is configured with a deploy target, and using version=GIT – see here for more information)
•    scrapy deploy dev
•    the developer goes into the panel and runs the spider, where he’ll see the branch name (issue123) that will be run
•    the developer checks the scraped data looks fine through the item browser in the panel
•    whenever issues are found, the developer makes more fixes (always working on the same branch) and deploys new versions
•    once all issues are fixed, the developer merges the branch and deploys to production project
•    git checkout master
•    git merge issue123
•    git pull # make sure to pull latest code before deploying
•    scrapy deploy prod

We recommend you keep your common spiders well-tested and use Spider Contracts extensively to test your final spiders. Otherwise experience tell us that base spiders end up being copied (instead of reused) out of fear of breaking old spiders that depend on them, thus turning their maintenance into a nightmare.

Source:http://blog.scrapinghub.com/2013/03/06/git-workflow-scrapy-projects/

Saturday, 13 December 2014

Handling exceptions in scrapers

When requesting and parsing data from a source with unknown properties and random behavior (in other words, scraping), I expect all kinds of bizarrities to occur. Managing exceptions is particularly helpful in such cases.

Here is some ways that an exception might be raised.
[][0] #The list has no zeroth element, so this raises an IndexError
{}['foo'] #The dictionary has no foo element, so this raises a KeyError

Catching the exception is sometimes cleaner than preventing it from happening in the first place. Here are some examples handling bizarre exceptions in scrapers.

Example 1: Inconsistant date formats

Let’s say we’re parsing dates.
import datetime
This doesn’t raise an error.
datetime.datetime.strptime('2012-04-19', '%Y-%m-%d')
But this does.
datetime.datetime.strptime('April 19, 2012', '%Y-%m-%d')

It raises a ValueError because the date formats don’t match. So what do we do if we’re scraping a data source with multiple date formats?

Ignoring unexpected date formats

A simple thing is to ignore the date formats that we didn’t expect.

import lxml.html
import datetime
def parse_date1(source):
    rawdate = lxml.html.fromstring(source).get_element_by_id('date').text
    try:
         cleandate = datetime.datetime.strptime(rawdate, '%Y-%m-%d')
    except ValueError:
         cleandate = None
    return cleandate

print parse_date1('<div id="date">2012-04-19</div>')

If we make a clean date column in a database and put this in there, we’ll have some rows with dates and some rows with nulls. If there are only a few nulls, we might just parse those by hand.

Trying multiple date formats

Maybe we have determined that this particular data source uses three different date formats. We can try all three.

import lxml.html
import datetime

def parse_date2(source):

    rawdate = lxml.html.fromstring(source).get_element_by_id('date').text

    for date_format in ['%Y-%m-%d', '%B %d, %Y', '%d %B, %Y']:

        try:
             cleandate = datetime.datetime.strptime(rawdate, date_format)
             return cleandate
        except ValueError:
             pass
    return None

print parse_date2('<div id="date">19 April, 2012</div>')

This loops through three different date formats and returns the first one that doesn’t raise the error.

Example 2: Unreliable HTTP connection

If you’re scraping an unreliable website or you are behind an unreliable internet connection, you may sometimes get HTTPErrors or URLErrors for valid URLs. Trying again later might help.

import urllib2
def load(url):
    retries = 3
    for i in range(retries):
        try:
            handle = urllib2.urlopen(url)
            return handle.read()
        except urllib2.URLError:
            if i + 1 == retries:
                raise
            else:
                time.sleep(42)
    # never get here

print load('http://thomaslevine.com')

This function tries to download the page thee times. On the first two fails, it waits 42 seconds and tries again. On the third failure, it raises the error. On a success, it returs the content of the page.

Example 3: Logging errors rather than raising them

For more complicated parses, you might find loads of errors popping up in weird places, so you might want to go through all of the documents before deciding which to fix first or whether to do some of them manually.

import scraperwiki
for document_name in document_names:
    try:
        parse_document(document_name)
    except Exception as e:
        scraperwiki.sqlite.save([], {
            'documentName': document_name,
            'exceptionType': str(type(e)),
            'exceptionMessage': str(e)
        }, 'errors')

This catches any exception raised by a particular document, stores it in the database and then continues with the next document. Looking at the database afterwards, you might notice some trends in the errors that you can easily fix and some others where you might hard-code the correct parse.

Example 4: Exiting gracefully

When I’m scraping over 9000 pages and my script fails on page 8765, I like to be able to resume where I left off. I can often figure out where I left off based on the previous row that I saved to a database or file, but sometimes I can’t, particularly when I don’t have a unique index.


for bar in bars:
    try:
        foo(bar)
    except:
        print('Failure at bar = "%s"' % bar)
        raise

This will tell me which bar I left off on. It’s fancier if I save the information to the database, so here is how I might do that with ScraperWiki.

import scraperwiki
resume_index = scraperwiki.sqlite.get_var('resume_index', 0)
for i, bar in enumerate(bars[resume_index:]):
    try:
        foo(bar)
    except:
        scraperwiki.sqlite.save_var('resume_index', i)
        raise
scraperwiki.sqlite.save_var('resume_index', 0)

ScraperWiki has a limit on CPU time, so an error that often concerns me is the scraperwiki.CPUTimeExceededError. This error is raised after the script has used 80 seconds of CPU time; if you catch the exception, you have two CPU seconds to clean up. You might want to handle this error differently from other errors.

import scraperwiki
resume_index = scraperwiki.sqlite.get_var('resume_index', 0)
for i, bar in enumerate(bars[resume_index:]):
    try:
        foo(bar)
    except scraperwiki.CPUTimeExceededError:
        scraperwiki.sqlite.save_var('resume_index', i)
    except Exception as e:
        scraperwiki.sqlite.save_var('resume_index', i)
        scraperwiki.sqlite.save([], {
            'bar': bar,
            'exceptionType': str(type(e)),
            'exceptionMessage': str(e)
        }, 'errors')
scraperwiki.sqlite.save_var('resume_index', 0)

tl;dr

Expect exceptions to occur when you are scraping a randomly unreliable website with randomly inconsistent content, and consider handling them in ways that allow the script to keep running when one document of interest is bizarrely formatted or not available.

Source: https://blog.scraperwiki.com/2012/05/handling-exceptions-in-scrapers/

Thursday, 11 December 2014

Scraping Webmaster Tools with FMiner

The biggest problem (after the problem with their data quality) I am having with Google Webmaster Tools is that you can’t export all the data for external analysis. Luckily the guys from the FMiner.com web scraping tool contacted me a few weeks ago to test their tool. The problem with Webmaster Tools is that you can’t use web based scrapers and all the other screen scraping software tools were not that good in the steps you need to take to get to the data within Webmaster Tools. The software is available for Windows and Mac OSX users.

FMiner is a classical screen scraping app, installed on your desktop. Since you need to emulate real browser behaviour, you need to install it on your desktop. There is no coding required and their interface is visual based which makes it possible to start scraping within minutes. Another possibility I like is to upload a set of keywords, to scrape internal search engine result pages for example, something that is missing in a lot of other tools. If you need to scrape a lot of accounts, this tool provides multi-browser crawling which decreases the time needed.

This tool can be used for a lot of scraping jobs, including Google SERPs, Facebook Graph search, downloading files & images and collecting e-mail addresses. And for the real heavy scrapers, they also have built in a captcha solving API system so if you want to pass captchas while scraping, no problem.

Below you can find an introduction to the tool, with one of their tutorial video’s about scraping IMDB.com:

More basic and advanced tutorials can be found on their website: Fminer tutorials. Their tutorials show you a range of simple and complex tasks and how to use their software to get the data you need.

Guide for Scraping Webmaster Tools data

The software is capable of dealing with JavaScript and AJAX, one of the main requirements to scrape data from within Google Webmaster Tools.

Step 1: The first challenge is to login into webmaster tools. After opening a new project, first browse to https://www.google.com/webmasters/ and select the Recording button in the upper left corner.

fminer01

After browsing to this page, a goto action appears in the left panel. Click on this button and look for the “Action Options” button at the bottom of that panel. Tick the option Clear cookies before do it to avoid problems if you are already logged in for example.

fminer06

Step 2: Click the “Sign in Webmaster Tools” button. You will notice the Macro designer overview on the left registered a click as the first step.

fminer03

Step 3: Fill in your Google username and password. In the designer panel you will see the two Fill actions emerging.

fminer04

Step 4: After this step you should add some waiting time to be sure everything is fully loaded. Use the second button on the right side above the Macro Designer panel to add an action. 2000 milliseconds (2 seconds :)) will do the job.

fminer07

fminer08

Step 5: Browse to the account of which you want to export the data from

fminer05

Step 6: Browse to the specific pages of which you want the data scraped

fminer09

Step 7:Scrape the data from the tables as shown in the video

Congratulations, now you are able to scrape data from Google Webmaster Tools :)

Step 8: One of the things I use it for is pulling the search query data per keyword, which you normally can’t export. To do that, you have to use a right mouse click on the keyword, which opens a menu with options. Go to open links recursively and select normal. This will loop through all the keywords.

fminer10

Step 9: This video will show you how to make use of the pagination elements to loop through all the pages:

You can also download the following file, which has a predefined set of actions to login in WMT and download the keywords, impressions and clicks: google_webmaster_tools_login.fmpx. Open the file and update the login details by clicking on those action buttons and insert your own Google account details.

Automating and scheduling scrapers

For people that want to automate and regularly download the data, you can setup a Scheduler config and within the project settings you can setup the program to send an e-mail after completion of the crawl:

Source: http://www.notprovided.eu/scraping-webmaster-tools-fminer/

Monday, 8 December 2014

Web scraping tutorial

There are three ways to access a website data. One is through a browser, the other is using a API (if the site provides one) and the last by parsing the web pages through code. The last one also known as Web Scraping is a technique of extracting information from websites using specially coded programs.

In this post we will take a quick look at writing a simple scraperusing the simplehtmldom library. But before we continue a word of caution:

Writing screen scrapers and spiders that consume large amounts of bandwidth, guess passwords, grab information from a site and use it somewhere else may well be a violation of someone’s rights and will eventually land you in trouble. Before writing  a screen scraper first see if the website offers an RSS feed or an API for the data you are looking. If not and you have to use a scraper, first check the websites policies regarding automated tools before proceeding.

Now that we have got all the legalities out of the way, lets start with the examples.

1. Installing simplehtmldom.

Simplehtmldom is a PHP library that facilitates the process of creating web scrapers. It is a HTML DOM parser written in PHP5 that let you manipulate HTML in a quick and easy way. It is a wonderful library that does away with the messy details of regular expressions and uses CSS selector style DOM access like those found in jQuery.

First download the library from sourceforge.  Unzip the library in you PHP includes directory or a directory where you will be testing the code.

Writing our first scraper.

Now that we are ready with the tools, lets write our first web scraper. For our initial idea let us see how to grab the sponsored links section from a google search page.

There are three ways to access a website data. One is through a browser, the other is using a API (if the site provides one) and the last by parsing the web pages through code. The last one also known as Web Scraping is a technique of extracting information from websites using specially coded programs.

In this post we will take a quick look at writing a simple scraperusing the simplehtmldom library. But before we continue a word of caution:

Writing screen scrapers and spiders that consume large amounts of bandwidth, guess passwords, grab information from a site and use it somewhere else may well be a violation of someone’s rights and will eventually land you in trouble. Before writing  a screen scraper first see if the website offers an RSS feed or an API for the data you are looking. If not and you have to use a scraper, first check the websites policies regarding automated tools before proceeding.

Source: http://www.codediesel.com/php/web-scraping-in-php-tutorial/

Monday, 1 December 2014

Why scraping and why TheWebMiner?

If you read this blog you are one of two things: you are either interested in web scraping and you have studied this domain for quite a while, or you are just curious about this relatively new field of interest and want to know what it is, how it’s done and especially why. Either way it’s fine!

In case you haven’t googled already this I can tell you that data extraction (or scraping) is a technique in which a computer program extracts data from human-readable output coming from another program (wikipedia). Basically it can collect all the information on a certain subject from certain places. It’s sort of the equivalent of ctrl+f, at the scale of the whole internet. It’s nothing like the search engines that we currently use because it can extract the data in a certain file, as excel, csv (coma separated values) or any other that the buyer wants, and also extracts only the relevant data, only the values that you are interested in.

I hope now that you understand the concept and you are wondering just why would you need such data. Well let’s take the example of an online store, pretty common nowadays, and of course the manager just like any manager wants his business to thrive, so, for that he has to keep up with the other online stores. Now the web scraping takes place: it is very useful for him to have, saved as excels all the competitor’s prices of certain products if not all of them. By this he can maintain a fair pricing policy and always be ahead of his competitors by knowing all of their prices and fluctuations.  Of course the data collecting can also be done manually but this is not effective because we are talking of thousand of products each one having its own page and so on. This is only one example of situation in which scrapping is useful but there are hundreds and each one of them it’s profitable for the company.

By now I’ve talked about what it is and why you should be interested in it, from now on I’m going to explain why you should use thewebminer.com. First of all, it’s easy: you only have to specify what type of data you want and from where and we’ll manage the rest. Throughout the project you will receive first of all an approximation of price, followed by a time approximation. All the time you will be in contact with us so you can find out at any point what is the state of your project. The pricing policy is reasonable and depends on factors like the project size or complexity. For very big projects a discount may be applicable so the total cost be within reason.

Now I believe that thewebminer.com is able to manage with any kind of situation or requirement from users all over the world and to convince you, free samples are available at any project you may have or any uncertainty or doubt.

Source:http://thewebminer.com/blog/2013/07/

Friday, 28 November 2014

Webscraping using readLines and RCurl

There is a massive amount of data available on the web. Some of it is in the form of precompiled, downloadable datasets which are easy to access. But the majority of online data exists as web content such as blogs, news stories and cooking recipes. With precompiled files, accessing the data is fairly straightforward; just download the file, unzip if necessary, and import into R. For “wild” data however, getting the data into an analyzeable format is more difficult. Accessing online data of this sort is sometimes reffered to as “webscraping”. Two R facilities, readLines() from the base package and getURL() from the RCurl package make this task possible.

readLines

For basic webscraping tasks the readLines() function will usually suffice. readLines() allows simple access to webpage source data on non-secure servers. In its simplest form, readLines() takes a single argument – the URL of the web page to be read:

web_page <- readLines("http://www.interestingwebsite.com")

As an example of a (somewhat) practical use of webscraping, imagine a scenario in which we wanted to know the 10 most frequent posters to the R-help listserve for January 2009. Because the listserve is on a secure site (e.g. it has https:// rather than http:// in the URL) we can't easily access the live version with readLines(). So for this example, I've posted a local copy of the list archives on the this site.

One note, by itself readLines() can only acquire the data. You'll need to use grep(), gsub() or equivalents to parse the data and keep what you need.

# Get the page's source
web_page <- readLines("http://www.programmingr.com/jan09rlist.html")
# Pull out the appropriate line
author_lines <- web_page[grep("<I>", web_page)]
# Delete unwanted characters in the lines we pulled out
authors <- gsub("<I>", "", author_lines, fixed = TRUE)
# Present only the ten most frequent posters
author_counts <- sort(table(authors), decreasing = TRUE)
author_counts[1:10]
[webscrape results]


We can see that Gabor Grothendieck was the most frequent poster to R-help in January 2009.

The RCurl package

To get more advanced http features such as POST capabilities and https access, you'll need to use the RCurl package. To do webscraping tasks with the RCurl package use the getURL() function. After the data has been acquired via getURL(), it needs to be restructured and parsed. The htmlTreeParse() function from the XML package is tailored for just this task. Using getURL() we can access a secure site so we can use the live site as an example this time.

# Install the RCurl package if necessary
install.packages("RCurl", dependencies = TRUE)
library("RCurl")
# Install the XML package if necessary
install.packages("XML", dependencies = TRUE)
library("XML")
# Get first quarter archives
jan09 <- getURL("https://stat.ethz.ch/pipermail/r-help/2009-January/date.html", ssl.verifypeer = FALSE)
jan09_parsed <- htmlTreeParse(jan09)
# Continue on similar to above
...

For basic webscraping tasks readLines() will be enough and avoids over complicating the task. For more difficult procedures or for tasks requiring other http features getURL() or other functions from the RCurl package may be required. For more information on cURL visit the project page here.

Source: http://www.r-bloggers.com/webscraping-using-readlines-and-rcurl-2/

Wednesday, 26 November 2014

Screen scrapers: To program or to purchase?

Companies today use screen scraping tools for a variety of purposes, including collecting competitive information, capturing product specs, moving data between legacy and new systems, and keeping inventory or price lists accurate.

Because of their popularity and reputation as being extremely efficient tools for quickly gathering applicable display data, screen scraping tools or browser add-ons are a dime a dozen: some free, some low cost, and some part of a larger solution. Alternatively, you can build your own if you are (or know) a programming whiz. Each tool has its potential pros and cons, however, to keep in mind as you determine which type of tool would best fit your business need.

Program-your-own screen scraper

Pros:

    Using in-house resources doesn't require additional budget

Cons:

    Properly creating scripts to automate screen scraping can take a significant amount of time initially, and continues to take time in order to maintain the process. If, for instance, objects from which you're gathering data move on a web page, the entire process will either need to be re-automated, or someone with programming acumen will have to edit the script every time there is a change.

    It's questionable whether or not this method actually saves time and resources

Free or cheap scrapers

Pros:

    Here again, budget doesn't ever enter the picture, and you can drive the process yourself.

    Some tools take care of at least some of the programming heavy lifting required to screen scrape effectively

Cons:

    Many inexpensive screen scrapers require that you get up to speed on their programming language—a time-consuming process that negates the idea of efficiency that prompted the purchase.

Screen scraping as part of a full automation solution

Pros:

    In the amount of time it takes to perform one data extraction task, you have a completely composed script that the system writes for you

    It's the easiest to use out of all of the options

    Screen scraping is only part of the package; you can leverage automation software to automate nearly any task or process including tasks in Windows, Excel automation, IT processes like uploads, backups, and integrations, and business processes like invoice processing.

    You're likely to get buy-in for other automation projects (and visibility for the efficiency you're introducing to the organization) if you pick a solution with a clear and scalable business purpose, not simply a tool to accomplish a single task.

Cons:

    This option has the highest price tag because of its comprehensive capabilities.

Looking for more information?

Here are some options to dig deeper into screen scraping, and deciding on the right tool for you:

 Watch a couple demos of what screen scraping looks like with an automation solution driving the process.

 Read our web data extraction guide for a complete overview.

 Try screen scraping today by downloading a free trial.

Source: https://www.automationanywhere.com/screen-scrapers

Sunday, 23 November 2014

Data Mining Outsourcing in a Better and Unique Approach

Data mining outsourcing services are ideal for clarity in various decision making processes.  It is the ultimate goal of any organization and business to increase on its profits as well as strengthen the bond with its customers. Equipping the business in such a way that it’s very easy to detect frauds and manage risks in a convenient manner is equally important. Volumes of data that are irrelevant or cannot be used when raw needs to be converted to a more useful form.  The data mining outsourcing services can greatly help you to analyze and interpret data in a more diligent way.

This service to reliable, experienced and qualified hands is very important. Your research project or engineering project can be easily and conveniently handled by experienced staff who guarantees you an accuracy level of about 98% and a massive reduction in operating costs. The quality of work is unsurpassed and the presentation is done in a format that is easy and simple for you. The project is done in a very short time alleviating you delays as well as ensuring on-time completion of your projects. To enjoy a successful outsourcing experience, you need to bank on a famous and reliable expertise.

The only time to rely with data mining outsourcing services is when you do not have a reliable, experienced expertise in your business.  Statistics indicate that it’s very easy to lose business intelligence or expose the privacy of the customers through this process. However companies which offer secure outsourcing process are on the increase as a result of massive competition. It’s an opportunity to develop your potential of sourced data and improve your business in all fields.

Data mining potential applications are infinite. However major applications are in the marketing research and scientific projects. It’s done both on large and small quantities of data by experienced staff well known for their best analytical procedures to guarantee you accurate and easy to use information. Data mining outsourcing services are the only perfect way to profitability.

Source:http://www.e-edge.biz/Data_Mining_Outsourcing_in_a_Better_and_Unique_Approach.html

Wednesday, 19 November 2014

NHL ending dry scraping of ice before overtime

TORONTO (AP) — The NHL will no longer dry scrape the ice before overtime.

Instituted this season in an effort to reduce the number of shootouts, the dry scraping will stop after Friday's games.

The general managers decided at their meeting Tuesday to make the change after the league talked to the players' union the past few days.

Beginning Saturday, ice crews around the league will again shovel the ice after regulation as they did in previous years. The GMs said the dry scrape was causing too much of a delay. Director of hockey operations Colin Campbell said the delays were lasting from more than four minutes to almost seven.

The dry scrape initially had been approved in hopes of reducing shootouts by improving scoring chances without unduly slowing play by recoating the ice.

The GMs also discussed expanded video review, including goaltender interference, and the possibility of three-on-three overtime. The American Hockey League is experimenting with the three-on-three format this season.

This annual meeting the day after the Hockey Hall of Fame induction usually doesn't produce actual changes, with the dry scrape providing an exception.

The main purpose is to set up the March meeting in Boca Raton, Florida, where these items will be further addressed.

Source:http://missoulian.com/sports/hockey/nhl-ending-dry-scraping-of-ice-before-overtime/article_3dd5473c-6102-5800-99f7-2c98be0f99ad.html

Monday, 17 November 2014

Scraping websites using the Scraper extension for Chrome

If you are using Google Chrome there is a browser extension for scraping web pages. It’s called “Scraper” and it is easy to use. It will help you scrape a website’s content and upload the results to google docs.

Walkthrough: Scraping a website with the Scraper extension
  •     Open Google Chrome and click on Chrome Web Store
  •     Search for “Scraper” in extensions
  •     The first search result is the “Scraper” extension
  •     Click the add to chrome button.
  •     Now let’s go back to the listing of UK MPs
  •     Open http://www.parliament.uk/mps-lords-and-offices/mps/
  •     Now mark the entry for one MP
  •     http://farm9.staticflickr.com/8490/8264509932_6cc8802992_o_d.png
  •     Right click and select “scrape similar…”
  •     http://farm9.staticflickr.com/8200/8264509972_f3a9e5d8e8_o_d.png
  •     A new window will appear – the scraper console
  •     http://farm9.staticflickr.com/8073/8263440961_9b94e63d56_b_d.jpg
  •     In the scraper console you will see the scraped content
  •     Click on “Save to Google Docs…” to save the scraped content as a Google Spreadsheet.
Walkthrough: extended scraping with the Scraper extension

Note: Before beginning this recipe – you may find it useful to understand a bit about HTML. Read our HTML primer.

Easy wasn’t it? Now let’s do something a little more complicated. Let’s say we’re interested in the roles a specific actress played. The source for all kinds of data on this is the IMDB (You can also search on sites like DBpedia or Freebase for this kinds of information; however, we’ll stick to IMDB to show the principle)

    Let’s say we’re interested in creating a timeline with all the movies the Italian actress Asia Argento ever starred; where do we start?

    The IMDB has a quite comprehensive archive of actors. Asia Argento’s site is: http://www.imdb.com/name/nm0000782/

    If you open the page you’ll see all the roles she ever played, together with a title and the year – let’s scrape this information

    Try to scrape it like we did above

    You’ll see the list comes out garbled – this is because the list here is structured quite differently.

    Go to the scraper console. Notice the small box on the upper left, saying XPath?

    XPath is a query language for HTML and XML.

    XPath can help you find the elements in the page you’re interested in – all you need to do is find the right element and then write the xpath for it.

    Now let’s assemble our table.

    You’ll see that our current Xpath – the one including the whole information is “//div[3]/div[3]/div[2]/div”

    http://farm9.staticflickr.com/8344/8264510130_ae31697fde_o_d.png

    Xpath is very simple it tells the computer to look at the HTML document and select <div> element number 3, then in this the third one, the second one and then all <div> elements (which if you count down our list, results in exactly where you are right now.
  •     However, we’d like to have the data separated out.
  •     To do this use the columns part of the scraper console…
  •     Let’s find our title first – look at the title using Inspect Element
  •     http://farm9.staticflickr.com/8355/8263441157_b4672d01b2_o_d.png
  •     See how the title is within a <b> tag? Let’s add the tag to our xpath.
  •     The expression seems to work well: let’s make this our first column
  •     In the “Columns” section, change the name of the first column to “title”
  •     Now let’s add the XPATH for the title to it
  •     The xpaths in the columns section are relative, that means “./b” will select the <b> element
  •     add “./b” to the xpath for the title column and click “scrape”
  •     http://farm9.staticflickr.com/8357/8263441315_42d6a8745d_o_d.png
  •     See how you only get titles?
  •     Now let’s continue for year? Years are within one <span>
  •     Create a new column by clicking on the small plus next to your “title” column
  •     Now create the “year” column with xpath “./span”
  •     http://farm9.staticflickr.com/8347/8263441355_89f4315a78_o_d.png
  •     Click on scrape and see how the year is added
  •     See how easily we got information out of a less structured webpage?
Source: http://schoolofdata.org/handbook/recipes/scraper-extension-for-chrome/

Sunday, 16 November 2014

Building Java Object Graph with Tour de France results – using screen scraping, java.util.Parser and assorted facilities

Last Saturday, the Tour de France 2011 departed. For people like myself, enjoying sports and working on Data Visualizations on the one hand and far fetched uses of SQL on the other, the Tour de France offers a wealth of data to work with: rankings for each stage in various categories, nationalities and teams to group by, distances and velocity, years to compare with one another and the like. So it has been my intention for some time to get hold of that data in a format I could work with.

Today I finally found some time to get it done. To locate the statistics for the Tour de France editions for the last few years and get them onto my laptop and into my database. This article describes the first part of that journey: how to get the stage results from some source on the internet into my locally running Java program in an appropriate object structure.

My starting point is the official Tour de France website:

Image

This website goes back to 2007 and also has the latest (2011) results. It presents the result in a format pleasing to the human eye – based on an HTML structure that is fairly pleasing to my groping Java code as well.

Analyzing the source of the Tour de France data

I start my explorations in Firefox, using the Firebug plugin. When I select the tab with the results for a particular stage, I inspect the (AJAX) call that is made to retrieve the stage results into the browser:

Image

The URL that was accessed is www.letour.fr/2010/TDF/LIVE/us/700/classement/ITE.html . When I access that URL directly, I see an HTML fragment with the individual ranking for the 7th stage in 2010. It turns out that with ITG instead of ITE in this URL, I get the overall ranking after the 7th Stage. Using IME in stead of ITE, I get the 7th stage’s climbers’ standing. And so on.

The HTML associated with the stage standing looks like this:

Image

Which is not as user friendly as the corresponding display in the browser:

Image

but still fairly well structured and programmatically interpretable.

Retrieving HTML fragments and parsing in Java

Consuming these HTML fragments with stage standings into my own Java code is very easy. Parsing the data and turning it into sensible Java Objects is slightly more work, but still quite feasible. From the Java Objects I next need to create a persistent storage for the data – that is the subject for another article.

Using the Java URL class and its openStream method to open an InputStream on whatever content can be found at the URL, it is dead easy to start reading the HTML from the Tour de France website into my Java program. I make use of the java.util.Scanner class to work my way through the HTML by Table Row (TR element). When you inspect the HTML fragments, it is clear early on that every individual rider’s entry corresponds with a TR element, so it seems only logical to have the Scanner break up the data by TR.

private static Stage processStage(int year, int stageSequence, Map<Integer, Rider> riders) throws java.io.IOException, java.net.MalformedURLException {

    String typeOfStanding = "ITE";
     URL stageStanding = new URL("http://www.letour.fr/"+year+"/TDF/LIVE/us/"
                                +(stageSequence==0?"0":stageSequence+"00") +
                                "/classement/"+typeOfStanding+".html");
    InputStream stream = stageStanding.openStream();
    Scanner scanner = new Scanner(stream);
    scanner.useDelimiter("</tr>");
    Stage stage = new Stage();
    stage.setSequence(stageSequence);
    boolean first = true;
    boolean firstStanding = true;
    while (scanner.hasNext()) {
        String entry = scanner.next();
        if (first) {
            first = false;
            Matcher regexMatcher = regexDistance.matcher(entry);
            if (regexMatcher.find()) {
                String distanceString = regexMatcher.group();
                stage.setTotalDistance(Float.parseFloat(distanceString.substring(0, distanceString.length() - 3)));
            }
        }
        if (!first) {
            String[] els = entry.split("/td>");
            if (els.length > 1) { // only the standing-entries have more than one td element
                Integer riderNumber = Integer.parseInt(extractValue(els[2]));

                Rider rider=null;
                if (riders.containsKey(riderNumber)) {
                    rider = riders.get(riderNumber);
                }
                else {
                    rider = new Rider(extractValue(els[1]),riderNumber, extractValue(els[3]));
                    riders.put(riderNumber,rider);
                }
                Standing standing =
                    new Standing(firstStanding ? 1 : (Integer.parseInt(extractValue(els[0]).replace(".", ""))),
                                  rider,extractValue(els[4]),
                                  extractValue(els[5]));
                firstStanding = false;
                stage.getStandings().add(standing);                }
        }
    } //while
    scanner.close();
    return stage;
}

Subsequently, the TR elements need to be broken up in the TD cell elements that contain the rank, rider’s name, their number, the team they ride for and the time for the stage as well as their lag with regard to the winner. I have used a simple split (on /td>) to extract the cells. The final logic for pulling the correct value from the cell is in the method extractValue. Note: this code is not very pretty, and I am not necessarily overly proud of it. On the other hand: it is one-time-use-only code and it is still fairly compact and easy to write and read.

private static String extractValue(String el) {
    String r = el.split("</")[0];
    if (r.lastIndexOf(">") > 0) {
        r = r.substring(r.lastIndexOf(">") + 1);
    }
    return r.split("<")[0];
}

I have created a few domain classes: Rider, Stage, Standing (as well as Tour) that are a business domain like representation of the Tour de France result data. Objects based on these classes are instantiated in the processStage method that is being invoked from the processTour method.

public static void processTour(Tour tour) throws IOException, MalformedURLException {
    if (tour.isPrologue())
      tour.getStages().add(processStage(tour.getYear(),0, tour.getRiders()));

    for (int i=1;i<= tour.getNumberOfStages();i++)  {
        tour.getStages().add(processStage(tour.getYear(),i, tour.getRiders()));
    }
}

When I run the TourManager class – a class that create a single Tour object for the Tour de France in 2010 –

public class TourManager {
     List<Tour> tours = new ArrayList<Tour>();
     public TourManager() {
        tours.add(new Tour(2010, 20, true));
        try {
            ProcessTourStandings.processTour(tours.get(0));
        } catch (MalformedURLException e) {
            System.out.println(e.getMessage());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
     public static void main(String[] args) {
        TourManager tm = new TourManager();
        for (Tour tour : tm.getTours()) {
            for (Stage stage : tour.getStages()) {
                System.out.println("================ Stage " + stage.getSequence() + "(" + stage.getTotalDistance() +
                                   " km)");
                for (Standing standing : stage.getStandings()) {
                    if (standing.getRank() < 4) {
                        System.out.println(standing.getRank() + "." + standing.getRider().getName());
                    }
                }
            }
        }
    }

it will print the top 3 in every stage:

Image

Source:http://technology.amis.nl/2011/07/04/building-java-object-graph-with-tour-de-france-results-using-screen-scraping-java-util-parser-and-assorted-facilities/

Friday, 14 November 2014

Scraping Data: Site-specific Extractors vs. Generic Extractors

Scraping is becoming a rather mundane job with every other organization getting its feet wet with it for their own data gathering needs. There have been enough number of crawlers built – some open-sourced and others internal to organizations for in-house utilities. Although crawling might seem like a simple technique at the onset, doing this at a large-scale is the real deal. You need to have a distributed stack set up to take care of handling huge volumes of data, to provide data in a low-latency model and also to deal with fail-overs. This still is achievable after crossing the initial tech barrier and via continuous optimizations. (P.S. Not under-estimating this part because it still needs a team of Engineers monitoring the stats and scratching their heads at times).

Social Media Scraping

Focused crawls on a predefined list of sites

However, you bump into a completely new land if your goal is to generate clean and usable data sets from these crawls i.e. “extract” data in a format that your DB can process and aid in generating insights. There are 2 ways of tackling this:

a. site-specific extractors which give desired results

b. generic extractors that result in few surprises

Assuming you still do focused crawls on a predefined list of sites, let’s go over specific scenarios when you have to pick between the two-

1. Mass-scale crawls; high-level meta data - Use generic extractors when you have a large-scale crawling requirement on a continuous basis. Large-scale would mean having to crawl sites in the range of hundreds of thousands. Since the web is a jungle and no two sites share the same template, it would be impossible to write an extractor for each. However, you have to settle in with just the document-level information from such crawls like the URL, meta keywords, blog or news titles, author, date and article content which is still enough information to be happy with if your requirement is analyzing sentiment of the data.

cb1c0_one-size

A generic extractor case

Generic extractors don’t yield accurate results and often mess up the datasets deeming it unusable. Reason being

programatically distinguishing relevant data from irrelevant datasets is a challenge. For example, how would the extractor know to skip pages that have a list of blogs and only extract the ones with the complete article. Or delineating article content from the title on a blog page is not easy either.

To summarize, below is what to expect of a generic extractor.

Pros-

minimal manual intervention

low on effort and time

can work on any scale

Cons-

Data quality compromised

inaccurate and incomplete datasets

lesser details suited only for high-level analyses

Suited for gathering- blogs, forums, news

Uses- Sentiment Analysis, Brand Monitoring, Competitor Analysis, Social Media Monitoring.

2. Low/Mid scale crawls; detailed datasets - If precise extraction is the mandate, there’s no going away from site-specific extractors. But realistically this is do-able only if your scope of work is limited i.e. few hundred sites or less. Using site-specific extractors, you could extract as many number of fields from any nook or corner of the web pages. Most of the times, most pages on a website share similar templates. If not, they can still be accommodated for using site-specific extractors.

cutlery

Designing extractor for each website

Pros-

High data quality

Better data coverage on the site

Cons-

High on effort and time

Site structures keep changing from time to time and maintaining these requires a lot of monitoring and manual intervention

Only for limited scale

Suited for gathering - any data from any domain on any site be it product specifications and price details, reviews, blogs, forums, directories, ticket inventories, etc.

Uses- Data Analytics for E-commerce, Business Intelligence, Market Research, Sentiment Analysis

Conclusion

Quite obviously you need both such extractors handy to take care of various use cases. The only way generic extractors can work for detailed datasets is if everyone employs standard data formats on the web (Read our post on standard data formats here). However, given the internet penetration to the masses and the variety of things folks like to do on the web, this is being overly futuristic.

So while site-specific extractors are going to be around for quite some time, the challenge now is to tweak the generic ones to work better. At PromptCloud, we have added ML components to make them smarter and they have been working well for us so far.

What have your challenges been? Do drop in your comments.

Source: https://www.promptcloud.com/blog/scraping-data-site-specific-extractors-vs-generic-extractors/

Thursday, 13 November 2014

Interactive Crawls for Scraping AJAX Pages on the Web

Crawling pages on the web has become an everyday affair for most enterprises. Too often do we come across offline businesses as well who’d like data gathered from the web for internal analyses. All this eventually to serve customers faster and better. At times, when the crawl job is high-end cum high-scale, businesses also consider DaaS providers to supplement their efforts.

However, the web landscape too has evolved with newer technologies that provide fancy experiences to web users. AJAX elements are one such common aid that leave even the DaaS providers perplexed. They come in various forms from a user’s point of view-

1. Load more results on the same page

2. Filter results based on various selection criteria

3. Submit forms, etc.

When crawling a non-AJAX page, simple GET requests do the job. However, AJAX pages work with POST requests that are not easy to trace for a normal bot.

Difference between GET request and POST request- Scraping

GET vs. POST

At PromptCloud, from our experience with a number of AJAX sites on the web, we’ve crossed the tech barrier. Below is a quick review about the challenges that come with AJAX crawling and its indicative solutions-

1. Javascript Emulations- A bot essentially emulates human browsing to fetch pages. When this needs to be done for Javascript components on a page, it gets tricky. Headless browser, which emulates human interaction with a web page without an interface, is the current approach. These browsers click on various elements/ dropdown lists that are embedded within Javascript code and capture responses to be transferred to programs. Which headless browser to pick depends on what fits well into your current stack.

2. Fetch Bandwidths- Unlike GET requests which complete pretty quickly, POST requests take quite a bit of time due to the number of events involved per fetch. Hence a good amount of bandwidth needs to be allocated in order to receive the response. For the same reason, wait times need to be taken care of too else you might end up with incomplete responses.

3. .NET Architectures- This is a more complex scenario related to maintaining the View State. Most of the postbacks come with an event and its validation. The bot needs to track the view state and pass validations for the event to occur so that the code can be executed and results captured. This is achieved by adopting a mechanism to restore states if things break midway.

4. Page Encoding- Request and response headers need to be taken care of on AJAX pages. The request needs to be sent in the exact format as expected by the server (Content-type or media type, accept fields, etc.) and similarly responses need to be parsed based on the content-type.

A Use Case

One of our clients who is into sale of event tickets at discounted rates had us crawl one of the ticketing sites on the web weekly; one of the most complex AJAX crawling we’ve dealt with so far. For the data that was to be extracted, multiple AJAX fetches were needed depending on the selections made. Requests had to be made for a combination of items from the dropdown box. These came with cookies and session IDs. To add to the challenge the site was extremely dynamic and changed its structure every week making it difficult for us to follow what data was where on the page.

We developed an AJAX crawler specific to this site to take care of all the dynamics. Response times were taken care of so that we didn’t miss any relevant information. We included an ML component to improve the crawler which is now pretty stable irrespective of changes on the site.

Overall, AJAX crawling requires more compute power in addition to the tech expertise. And because there’s no uniformity on the web, there’s always a new challenge to overcome in this landscape. It wouldn’t be an overrating if we said we’ve done a good job at that so far and have developed the knack :)

Reach out to us for any kind of web scraping/ crawling- either AJAX or not. We’ll take care of the complexities.

Source: https://www.promptcloud.com/blog/web-scraping-interactive-ajax-crawls/

Wednesday, 12 November 2014

Web scraping services-importance of scraped data

Web scraping services are provided by computer software which extracts the required facts from the website. Web scraping services mainly aims at converting unstructured data collected from the websites into structured data which can be stockpiled and scrutinized in a centralized databank. Therefore, web scraping services have a direct influence on the outcome of the reason as to why the data collected in necessary.

It is not very easy to scrap data from different websites due to the terms of service in place. So, the there are some legalities that have been improvised to protect altering the personal information on different websites. These ‘rules’ must be followed to the letter and to some extent have limited web scraping services.

Owing to the high demand for web scraping, various firms have been set up to provide the efficient and reliable guidelines on web scraping services so that the information acquired is correct and conforms to the security requirements. The firms have also improvised different software that makes web scraping services much easier.

Importance of web scraping services

Definitely, web scraping services have gone a long way in provision of very useful information to various organizations. But business companies are the ones that benefit more from web scraping services. Some of the benefits associated with web scraping services are:

    Helps the firms to easily send notifications to their customers including price changes, promotions, introduction of a new product into the market. Etc.
    It enables firms to compare their product prices with those of their competitors
    It helps the meteorologists to monitor weather changes thus being able to focus weather conditions more efficiently
    It also assists researchers with extensive information about peoples’ habits among many others.
    It has also promoted e-commerce and e-banking services where the rates of stock exchange, banks’ interest rates, etc. are updated automatically on the customer’s catalog.

Advantages of web scraping services

The following are some of the advantages of using web scraping services

    Automation of the data

    Web scraping can retrieve both static and dynamic web pages

    Page contents of various websites can be transformed

    It allows formulation of vertical aggregation platforms thus even complicated data can still be extracted from different websites.

    Web scraping programs recognize semantic annotation

    All the required data can be retrieved from their websites

    The data collected is accurate and reliable

Web scraping services mainly aims at collecting, storing and analyzing data. The data analysis is facilitated by various web scrapers that can extract any information and transform it into useful and easy forms to interpret.

Challenges facing web scraping

    High volume of web scraping can cause regulatory damage to the pages

    Scale of measure; the scales of the web scraper can differ with the units of measure of the source file thus making it somewhat hard for the interpretation of the data

    Level of source complexity; if the information being extracted is very complicated, web scraping will also be paralyzed.

It is clear that besides web scraping providing useful data and information, it experiences a number of challenges. The good thing is that the web scraping services providers are always improvising techniques to ensure that the information gathered is accurate, timely, reliable and treated with the highest levels of confidentiality.

Source: http://www.loginworks.com/blogs/web-scraping-blogs/191-web-scraping-services-importance-of-scraped-data/

Monday, 10 November 2014

How to scrape Amazon with WebDriver in Java

Here is a real-world example of using Selenium WebDriver for scraping.
This short program is written in Java and scrapes book title and author from the Amazon webstore.
This code scrapes only one page, but you can easily make it scraping all the pages by adding a couple of lines.

You can download the souce here.

import java.io.*;
import java.util.*;
import java.util.regex.*;

import org.openqa.selenium.*;
import org.openqa.selenium.firefox.FirefoxDriver;


public class FetchAllBooks {

    public static void main(String[] args) throws IOException {

        WebDriver driver = new FirefoxDriver();
      

driver.navigate().to("http://www.amazon.com/tag/center%20right?ref_=tag_dpp_cust_itdp_s_t&sto

re=1");

        List<WebElement> allAuthors =  driver.findElements(By.className("tgProductAuthor"));
        List<WebElement> allTitles =  driver.findElements(By.className("tgProductTitleText"));
        int i=0;
        String fileText = "";

        for (WebElement author : allAuthors){
            String authorName = author.getText();
            String Url = (String)((JavascriptExecutor)driver).executeScript("return

arguments[0].innerHTML;", allTitles.get(i++));
            final Pattern pattern = Pattern.compile("title=(.+?)>");
            final Matcher matcher = pattern.matcher(Url);
            matcher.find();
            String title = matcher.group(1);
            fileText = fileText+authorName+","+title+"\n";
        }

        Writer writer = new BufferedWriter(new OutputStreamWriter(new

FileOutputStream("books.csv"), "utf-8"));
        writer.write(fileText);
        writer.close();

        driver.close();
    }
}

Source: http://scraping.pro/scraping-amazon-webdriver-java/

Saturday, 8 November 2014

Web Scraping Enters Politics

Web scraping is becoming an essential tool in gaining an edge over everything about just anything. This is proven by international news on US political campaigns, specifically by identifying wealthy donors. As is commonly known, election campaigns should follow a rule regarding the use of a certain limited amount of money for the expenses of each candidate. Being so, much of the campaign activities must be paid by supporters and sponsors.

It is not a surprise then that even politics is lured to make use of the dynamic and ever growing data mining processes. Once again, web mining has proven to be an essential component of almost all levels of human existence, the society, and the world as a whole. It proves its extraordinary capacity to dig precious information to reach the much aspired for goals of every individual.

Mining for personal information

The CBC News online very recently disclosed that the US Republican presidential candidate Mitt Romney has used data mining in order to identify rich donors. It is reported that the act of getting personal information such as the buying history and church attendance were vital in this incident. Through this information, the party was able to identify prospective rich donors and indeed tap them. As a businessman himself, Romney knows exactly how to fish and where the fat fish are. Moreover, what is unique about the identified donors is that they have never been donating before.

Source:http://www.loginworks.com/blogs/web-scraping-blogs/web-scraping-enters-politics/

Wednesday, 5 November 2014

Web Scraping: The Invaluable Decision Making Tool

Business decisions are mandatory in any company. They reflect and directly influence about the future of the company. It is important to realize that decisions must be made in any business situation. The generation of new ideas calls for new actions. This in turn calls for decisions. Decisions can only be made when there is adequate information or data regarding the problem and the cause of action to be taken. Web scraping offers the best opportunity in getting the required information that will enable the management make a wise and sound decision.

Therefore web scraping is an important part in generation of the practical interpretations for the business decision making process. Since businesses take many courses of actions the following areas call for adequate web scraping in order to make outstanding decisions.

1. Suppliers. Whether you are running an offline business there is need to get information regarding your suppliers. In this case there are two situations. The first situation is about your current suppliers and the second situation is about the possibility of acquiring new suppliers. By web scraping you has the opportunity to gather about your suppliers. You need to know other business they are supplying to and the kind of discounts and prices they offer to them. Another important aspect about consumers is to determine the periods when they have surplus and therefore be able to determine the purchasing prices.

Web scraping can provide new information concerning new suppliers. This will make a cutting edge in the purchasing sector. You can get new suppliers that have reasonable prices. This will go a long way in ensuring a profitable business. Therefore web scraping is an integral process that should be taken first before making a vital decision concerning suppliers.

Source:http://www.loginworks.com/blogs/web-scraping-blogs/web-scraping-invaluable-decision-making-tool/

Thursday, 11 September 2014

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

Monday, 8 September 2014

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