How to extract data from web 2.0 graphs using a scraper

I have recently come across a web page containing a graph object that displays the (x, y) values on the object as the

mouse is rolled across it. Is there any way to automate the extraction of this data?

How is the graph data loaded? If embedded in the page source then you can extract it with xpath or regex. Else use

Firebug to see how it is loaded.



You will need a solution that works inside the web browser, so the AJAX/Javascript is properly rendered.

I have used iMacros with good success for web scraping in the past. There are free/open-source and "PRO" paid editions

(comparison table here).

Another option is always to custom code something with the Microsoft webbrowser control.


Source: http://stackoverflow.com/questions/3980774/how-to-extract-data-from-web-2-0-graphs-using-a-scraper

Legality of Web Scraping vs Normal Use

I know the topic of web scraping has been discussed before (example), and I understand it's a bit of a grey area

depending on a lot of factors (e.g. website's terms of use).

What I'd like to ask is: how is web scraping any different from (a) how we access the webpage via a web browser, and

(b) how web crawlers (e.g. Google) download and index webpages?

Without knowing the legal background, I can't help but think that they're all just HTTP requests. If web scraping is

illegal, then so should crawling and indexing (for instance be illegal).

Of course if your program is hitting the server so hard that it causes a denial of service, it's a different story

altogether... my point is simply accessing and using data that is already open to the public.



I know this is a dead thread, but it would be nice to place some legal implications here due to its ranking in my

Google Search. I cannot help but figure I am not the only one who searches like I do.

Legally, in the US, there are a few factors that seem to be important.

    Are you doing anything that is akin to hacking or gaining unauthorized access via the Computer Fraud and Abuse Act.

Exploiting vulnerabilities and passing SQL in the URL to open a database no matter how bad the idiot programming like

that was is illegal with a 15 year sentence (see the cases where an individual exploited security vulnerabilities in

Verizon). Also, add a time out even if you round robin or use proxies. DDoS attacks are attacks. 1000 requests per

second can shut down a lot of servers providing public information. The result here is up to 15 years in jail.

    Copyright Law: As mentioned, pure replication of data is illegal. Even 4% replication has been deemed a breach.

With the recent gutting of the DMCA, a person is even more vulnerable to civil and criminal penalties.

    Trespass and Chattels: The following from wikipedia says it all.

    U.S. courts have acknowledged that users of "scrapers" or "robots" may be held liable for committing trespass to

chattels,[5][6] which involves a computer system itself being considered personal property upon which the user of a

scraper is trespassing. The best known of these cases, eBay v. Bidder's Edge, resulted in an injunction ordering

Bidder's Edge to stop accessing, collecting, and indexing auctions from the eBay web site.

    Paywalls and Product: When going behind paywalls and breaching contract by clicking an agreement not to do

something and then doing it, you add fuel to the protection of negligence v. willingness [an issue for damages and

penalties not guilt] in civil and any criminal trials. (sorry originally wanted to say ignorance but it really isn't a

defense)

    International: EU law and other law is way more lax. Corporations with big budgets dominate our legal landscape.

They control the system in a very real way with their $$$.

Basically, get public information and information that is available without going behind a pay wall. Think like a user

of the internet and combine a bunch of sources into a unique product. Don't just 'steal' an entire site (it isn't

really stealing if it is a government site that offers public data especially for download but is if you download all

or even more than a couple of the listings on ebay). Read the terms and conditions to know who actually owns the

content.

Here are a few examples. Trulia owns its information but you could use it to go to an agents website and collect a

legal amount of information. The legal amount is determinable. However, a public MLS listing lookup site with no

agreement or terms and offering data to the public is fair game. The MLS numbers lists, however, are normally not fair

game.

If a researcher can get to data, so can you. If a researcher needs permission, so do you. A computer is like having a

million corporate researchers at your disposal.

AS for company policy, it is usually used internally to shield from liability and serves as a warning but is not

entirely enforceable. The legal parts letting you know about copyrights and such are and usually are supposed to be

known by everyone. Complete ignorance is not a legal protection. It does provide a ground set of rules. Be nice, or get

banned is that message as far as I know.

My personal strategy is to start with public data and embellish it within legal means.


Source: http://stackoverflow.com/questions/14735791/legality-of-web-scraping-vs-normal-use

Anyone knows an online tool that can scrape a page and create a REST API for the scraped data?

I'm looking for a SaaS solution that is able to login to a platform, scrape data (reports) and then allow accessing the

data through an API. I have some reporting platforms that provide web reporting and email reporting but with no API.

Online reporting doesn't help and email reporting, although can be automated and scraped, isn't so reliable.

If you are willing to do the scraping through your own connection, have a look at Import IO. They have a desktop

application that you use to teach the system how to scrape a page, and then you run the crawler from that application -

and you can run it for as long as you like, as far as I can tell.

You may then upload your data to the Import cloud, from where it is available via an API on the import.io servers.

Useful data can be made public to donate it "to the commons" if you wish.


I did some more digging, found iMacros as a possible solution. Its Windows based, which is a drawback in my case, but

it does allow automation of the scraping and afterwards interaction via common web scripting languages like PHP and

ASP.net.


If you are familiar with jQuery, I think you can use node.js and Cheerio module, then you can create a simple

application to do auto scraping. Actually I have already built a site to do on line web scraping based on the above

mentioned tech, the site is www.datafiddle.net, you can take a look at it.


Source: http://stackoverflow.com/questions/19646028/anyone-knows-an-online-tool-that-can-scrape-a-page-and-create-a-

rest-api-for-the

Extract data from Web Scraping C#

I am MVC ASP.NET developer.

I have received the contents from any url, i.e. http, https etc. using WebRequest class.

I have received all the content of that particular url. (for now I took http://google.com)

My next step is to extract buttons, header, footer, colors, text etc.

Here is my code for now:

public ActionResult GetContent(UrlModel model) //model having a string URL
which is entered in a text box and method hits using submit button.
{
    //WebRequest request = WebRequest.Create(model.URL);

    WebRequest request = WebRequest.Create(model.URL);

    request.Credentials = CredentialCache.DefaultCredentials;

    WebResponse response = request.GetResponse();

    Stream dataStream = response.GetResponseStream();

    StreamReader reader = new StreamReader(dataStream);

    string responseFromServer = reader.ReadToEnd();
    ViewBag.Response = responseFromServer;

    reader.Close();
    response.Close();
    return View();
}

Can someone help me with writing the code ?

Also do suggest me with some techniques of data extraction in C#.



Source: http://stackoverflow.com/questions/21901162/extract-data-from-web-scraping-c-sharp

Scrapy, scraping price data from StubHub

I've been having a difficult time with this one.

I want to scrape all the prices listed for this Bruno Mars concert at the Hollywood Bowl so I can get the average price.

http://www.stubhub.com/bruno-mars-tickets/bruno-mars-hollywood-hollywood-bowl-31-5-2014-4449604/

I've located the prices in the HTML and the xpath is pretty straightforward but I cannot get any values to return.

I think it has something to do with the content being generated via javascript or ajax but I can't figure out how to send the correct request to get the code to work.

Here's what I have:

from scrapy.spider import BaseSpider
from scrapy.selector import Selector

from deeptix.items import DeeptixItem

class TicketSpider(BaseSpider):
    name = "deeptix"
    allowed_domains = ["stubhub.com"]
    start_urls = ["http://www.stubhub.com/bruno-mars-tickets/bruno-mars-hollywood-hollywood-bowl-31-5-2014-4449604/"]

def parse(self, response):
    sel = Selector(response)
    sites = sel.xpath('//div[contains(@class, "q_cont")]')
    items = []
    for site in sites:
        item = DeeptixItem()
        item['price'] = site.xpath('span[contains(@class, "q")]/text()').extract()
        items.append(item)
    return items

Any help would be greatly appreciated I've been struggling with this one for quite some time now. Thank you in advance!


Source: http://stackoverflow.com/questions/22770917/scrapy-scraping-price-data-from-stubhub

How do you scrape AJAX pages?

Overview:

All screen scraping first requires manual review of the page you want to extract resources from. When dealing with AJAX you usually just need to analyze a bit more than just simply the HTML.

When dealing with AJAX this just means that the value you want is not in the initial HTML document that you requested, but that javascript will be exectued which asks the server for the extra information you want.

You can therefore usually simply analyze the javascript and see which request the javascript makes and just call this URL instead from the start.

Example:

Take this as an example, assume the page you want to scrape from has the following script:

<script type="text/javascript">
function ajaxFunction()
{
var xmlHttp;
try
  {
  // Firefox, Opera 8.0+, Safari
  xmlHttp=new XMLHttpRequest();
  }
catch (e)
  {
  // Internet Explorer
  try
    {
    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
  catch (e)
    {
    try
      {
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
      }
    catch (e)
      {
      alert("Your browser does not support AJAX!");
      return false;
      }
    }
  }
  xmlHttp.onreadystatechange=function()
    {
    if(xmlHttp.readyState==4)
      {
      document.myForm.time.value=xmlHttp.responseText;
      }
    }
  xmlHttp.open("GET","time.asp",true);
  xmlHttp.send(null);
  }
</script>

Then all you need to do is instead do an HTTP request to time.asp of the same server instead. Example from w3schools.


Sporce: http://stackoverflow.com/questions/260540/how-do-you-scrape-ajax-pages

using Perl to scrape a website

I am interested in writing a perl script that goes to the following link and extracts the number 1975: https://familysearch.org/search/collection/results#count=20&query=%2Bevent_place_level_1%3ACalifornia%20%2Bevent_place_level_2%3A%22San%20Diego%22%20%2Bbirth_year%3A1923-1923~%20%2Bgender%3AM%20%2Brace%3AWhite&collection_id=2000219

That website is the amount of white men born in the year 1923 who live in San Diego County, California in 1940. I am trying to do this in a loop structure to generalize over multiple counties and birth years.

In the file, locations.txt, I put the list of counties, such as San Diego County.

The current code runs, but instead of the # 1975, it displays unknown. The number 1975 should be in $val\n.

I would very much appreciate any help!

#!/usr/bin/perl

use strict;

use LWP::Simple;

open(L, "locations26.txt");

my $url = 'https://familysearch.org/search/collection/results#count=20&query=%2Bevent_place_level_1%3A%22California%22%20%2Bevent_place_level_2%3A%22%LOCATION%%22%20%2Bbirth_year%3A%YEAR%-%YEAR%~%20%2Bgender%3AM%20%2Brace%3AWhite&collection_id=2000219';

open(O, ">out26.txt");
 my $oldh = select(O);
 $| = 1;
 select($oldh);
 while (my $location = <L>) {
     chomp($location);
     $location =~ s/ /+/g;
      foreach my $year (1923..1923) {
                 my $u = $url;
                 $u =~ s/%LOCATION%/$location/;
                 $u =~ s/%YEAR%/$year/;
                 #print "$u\n";
                 my $content = get($u);
                 my $val = 'unknown';
                 if ($content =~ / of .strong.([0-9,]+)..strong. /) {
                         $val = $1;
                 }
                 $val =~ s/,//g;
                 $location =~ s/\+/ /g;
                 print "'$location',$year,$val\n";
                 print O "'$location',$year,$val\n";
         }
     }

Update: API is not a viable solution. I have been in contact with the site developer. The API does not apply to that part of the webpage. Hence, any solution pertaining to JSON will not be applicbale.



Source: http://stackoverflow.com/questions/14654288/using-perl-to-scrape-a-website