Wednesday, 27 August 2014

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

Tuesday, 26 August 2014

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

Monday, 25 August 2014

Data Scraping using php


Here is my code

    $ip=$_SERVER['REMOTE_ADDR'];

    $url=file_get_contents("http://whatismyipaddress.com/ip/$ip");

    preg_match_all('/<th>(.*?)<\/th><td>(.*?)<\/td>/s',$url,$output,PREG_SET_ORDER);

    $isp=$output[1][2];

    $city=$output[9][2];

    $state=$output[8][2];

    $zipcode=$output[12][2];

    $country=$output[7][2];

    ?>
    <body>
    <table align="center">
    <tr><td>ISP :</td><td><?php echo $isp;?></td></tr>
    <tr><td>City :</td><td><?php echo $city;?></td></tr>
    <tr><td>State :</td><td><?php echo $state;?></td></tr>
    <tr><td>Zipcode :</td><td><?php echo $zipcode;?></td></tr>
    <tr><td>Country :</td><td><?php echo $country;?></td></tr>
    </table>
    </body>

How do I find out the ISP provider of a person viewing a PHP page?

Is it possible to use PHP to track or reveal it?

Error: http://i.imgur.com/LGWI8.png

Curl Scrapping

<?php
$curl_handle=curl_init();
curl_setopt( $curl_handle, CURLOPT_FOLLOWLOCATION, true );
$url='http://www.whatismyipaddress.com/ip/132.123.23.23';
curl_setopt($curl_handle, CURLOPT_URL,$url);
curl_setopt($curl_handle, CURLOPT_HTTPHEADER, Array("User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.15) Gecko/20080623 Firefox/2.0.0.15") );
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl_handle, CURLOPT_USERAGENT, 'Your application name');
$query = curl_exec($curl_handle);

curl_close($curl_handle);
preg_match_all('/<th>(.*?)<\/th><td>(.*?)<\/td>/s',$url,$output,PREG_SET_ORDER);
echo $query;
$isp=$output[1][2];

$city=$output[9][2];

$state=$output[8][2];

$zipcode=$output[12][2];

$country=$output[7][2];
?>
<body>
<table align="center">
<tr><td>ISP :</td><td><?php echo $isp;?></td></tr>
<tr><td>City :</td><td><?php echo $city;?></td></tr>
<tr><td>State :</td><td><?php echo $state;?></td></tr>
<tr><td>Zipcode :</td><td><?php echo $zipcode;?></td></tr>
<tr><td>Country :</td><td><?php echo $country;?></td></tr>
</table>
</body>

Error: http://i.imgur.com/FJIq6.png

What's is wrong with my code here? Any alternative code , that i can use here.

I am not able to scrape that data as described here. http://i.imgur.com/FJIq6.png

P.S. Please post full code. It would be easier for me to understand.



Source: http://stackoverflow.com/questions/10461088/data-scraping-using-php

PDF scraping using R


I have been using the XML package successfully for extracting HTML tables but want to extend to PDF's. From previous questions it does not appear that there is a simple R solution but wondered if there had been any recent developments

Failing that, is there some way in Python (in which I am a complete Novice) to obtain and manipulate pdfs so that I could finish the job off with the R XML package

Extracting text from PDFs is hard, and nearly always requires lots of care.

I'd start with the command line tools such as pdftotext and see what they spit out. The problem is that PDFs can store the text in any order, can use awkward font encodings, and can do things like use ligature characters (the joined up 'ff' and 'ij' that you see in proper typesetting) to throw you.

pdftotext is installable on any Linux system



Source: http://stackoverflow.com/questions/7918718/pdf-scraping-using-r

Sunday, 24 August 2014

Php Scraping data from a website

I am very new to programming and need a little help with getting data from a website and passing it into my PHP script.

The website is http://www.birthdatabase.com/.

I would like to plug in a name (First and Last) and retrieve the result. I know you can query the site by passing the name in the URL, but I am having problems scraping the results.

http://www.birthdatabase.com/cgi-bin/query.pl?textfield=FIRST&textfield2=LAST&age=&affid=

I am using the file_get_contents($URL) function to get the page but need help after that. Specifically, I would like to scrape only the results from a certain state if there are multiple results for that name.



You need the awesome simple_html_dom class.

With this class you can query the webpage's DOM in a similar way to jQuery.

First include the class in your page, then get the page content with this snippet:

$html = file_get_html('http://www.birthdatabase.com/cgi-bin/query.pl?textfield=' . $first . '&textfield2=' . $last . '&age=&affid=');

Then you can use CSS selections to scrape your data (something like this):

$n = 0;
foreach($html->find('table tbody tr td div font b table tbody') as $element) {
    @$row[$n]['tr']  = $element->find('tr')->text;
    $n++;
}

// output your data
print_r($row);



Source: http://stackoverflow.com/questions/15601584/php-scraping-data-from-a-website

Obtaining reddit data

I am interested in obtaining data from different reddit subreddits. Does anyone know

if there is a reddit/other api similar like twitter does to crawl all the pages?


Yes, reddit has an API that can be used for a variety of purposes such as data

collection, automatic commenting bots, or even to assist in subreddit moderation.

There are a few places to discover information on reddit's API:

    github reddit wiki -- provides the overview and rules for using reddit's API

(follow the rules)
    automatically generated API docs -- provides information on the requests needed to

access most of the API endpoints
    /r/redditdev -- the reddit community dedicated to answering questions both about

reddit's source code and about reddit's API

If there is a particular programming language you are already familiar with, you

should check out the existing set of API wrappers for various languages. Despite my

bias (I am the package maintainer) I am quite certain PRAW, for python, has support

for the largest number of reddit API features.



Source: http://stackoverflow.com/questions/14322834/obtaining-reddit-data

Tuesday, 19 August 2014

Scrape Data Point Using Python

I am looking to scrape a data point using Python off of the url http://www.cavirtex.com/orderbook .

The data point I am looking to scrape is the lowest bid offer, which at the current moment looks like this:

<tr>
 <td><b>Jan. 19, 2014, 2:37 a.m.</b></td>
 <td><b>0.0775/0.1146</b></td>
 <td><b>860.00000</b></td>
 <td><b>66.65 CAD</b></td>
</tr>

The relevant point being the 860.00 . I am looking to build this into a script which can send me an email to alert me of certain price differentials compared to other exchanges.

I'm quite noobie so if in your explanations you could offer your thought process on why you've done certain things it would be very much appreciated.

Thank you in advance!

Edit: This is what I have so far which will return me the name of the title correctly, I'm having trouble grabbing the table data though.

import urllib2, sys
from bs4 import BeautifulSoup

site= "http://cavirtex.com/orderbook"
hdr = {'User-Agent': 'Mozilla/5.0'}
req = urllib2.Request(site,headers=hdr)
page = urllib2.urlopen(req)
soup = BeautifulSoup(page)
print soup.title



Here is the code for scraping the lowest bid from the 'Buying BTC' table:

from selenium import webdriver

fp = webdriver.FirefoxProfile()
browser = webdriver.Firefox(firefox_profile=fp)
browser.get('http://www.cavirtex.com/orderbook')

lowest_bid = float('inf')
elements = browser.find_elements_by_xpath('//div[@id="orderbook_buy"]/table/tbody/tr/td')

for element in elements:
    text = element.get_attribute('innerHTML').strip('<b>|</b>')
    try:
        bid = float(text)
        if lowest_bid > bid:
            lowest_bid = bid
    except:
        pass

browser.quit()
print lowest_bid

In order to install Selenium for Python on your Windows-PC, run from a command line:

pip install selenium (or pip install selenium --upgrade if you already have it).

If you want the 'Selling BTC' table instead, then change "orderbook_buy" to "orderbook_sell".

If you want the 'Last Trades' table instead, then change "orderbook_buy" to "orderbook_trades".

Note:

If you consider performance critical, then you can implement the data-scraping via URL-Connection instead of Selenium, and have your program running much faster. However, your code will probably end up being a lot "messier", due to the tedious XML parsing that you'll be obliged to apply...

Here is the code for sending the previous output in an email from yourself to yourself:

import smtplib,ssl

def SendMail(username,password,contents):
    server = Connect(username)
    try:
        server.login(username,password)
        server.sendmail(username,username,contents)
    except smtplib.SMTPException,error:
        Print(error)
    Disconnect(server)

def Connect(username):
    serverName = username[username.index("@")+1:username.index(".")]
    while True:
        try:
            server = smtplib.SMTP(serverDict[serverName])
        except smtplib.SMTPException,error:
            Print(error)
            continue
        try:
            server.ehlo()
            if server.has_extn("starttls"):
                server.starttls()
                server.ehlo()
        except (smtplib.SMTPException,ssl.SSLError),error:
            Print(error)
            Disconnect(server)
            continue
        break
    return server

def Disconnect(server):
    try:
        server.quit()
    except smtplib.SMTPException,error:
        Print(error)

serverDict = {
    "gmail"  :"smtp.gmail.com",
    "hotmail":"smtp.live.com",
    "yahoo"  :"smtp.mail.yahoo.com"
}

SendMail("your_username@your_provider.com","your_password",str(lowest_bid))

The above code should work if your email provider is either gmail or hotmail or yahoo.

Please note that depending on your firewall configuration, it may ask your permission upon the first time you try it...



Source: http://stackoverflow.com/questions/21217034/scrape-data-point-using-python

Sunday, 17 August 2014

How to prevent data-scraping a valuable data web service?

I have a great idea for a windows store app. I'd like to make this app. However it requires a large and valuable database that I will need to create a service for so that people cannot easily steal it. My thinking is maybe host a mobile service on Azure (which I've never tried) and create a .net Web API project to take requests and dish out Json like candy to a windows 8 mvvmclient. However what I don't want is someone sniffing my traffic back and forth from app to service and figuring out how to get/post data from using my app and service then setting up their own app / website to display this data using my bandwidth to make them money.

How can I protect my app-to-db data access so it can't be reverse engineered on me.

Also is this the best setup for developing a high volume windows 8 app like this? Do you have a better suggestion?

EDIT: I know I can use SSL etc to encrypt traffic to and from. What I am trying to protect is someone using Firebug or Fiddler to figure out what parameters can be posted to get a particular record back. Then creating their own site that simply uses my service as the end point and siphons my data and whores my bandwidth. ie. Just using firebug I know I can use https://www.google.com/search?q=dallas to search the word dallas on google. Even if I encrypt the page, they can see that much in their browser. so if someone does the same get/post in their own application they would get the same records back thus using my stuff.

3 Answers

The most straight forward thing you can do is to setup authentication for your users using something like OAuth. This will allow you to ensure no communication happens with your service in an anonymous fashion.

Once you have authenticated your requests you can place controls on those requests that won't impact a normal user. You could rate limit or throttle requests or any number of tactics to make it very expensive time wise to siphon off large portions of your data set.

For instance, you can start blocking requests when you notice a large number of users clustering from a single IP address. You could place sensible limits on each user (like 10 API calls per minute with a result set limited to 50). You get the idea I'm sure.

I think we met the same concern. I'm developing a windows 8 application which is contacting a web service built on top of Windows Azure Web Site. I don't want the bad guy fire some fake requests to my service by intercepting the traffic through some tools like Fiddler.

I asked this question in a mail group and got a tip. I've never tried but just for your information. If your application needs user login, then the user's password is a good seed for data/traffic protection. You can use the password to generate a key-pair, sign the request and send it to server as well as the public key. Then on the server side it can verify the sign by the public key.

Use HTTPS is another approach. But as you know, a bad guy can also know the actual data through Fiddler even though HTTPS.

Use certificate might be another solution I think. But I didn't find the relevant document on how to install and pick a certificate from client's machine.

HTH

just serve it over HTTPS, then they can't sniff it.

Source:http://stackoverflow.com/questions/14350298/how-to-prevent-data-scraping-a-valuable-data-web-service