HotelClub Data Scraping

Sunday, 24 August 2014

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

Saturday, 23 August 2014

Scraping data in dynamic sites

I'm trying to scrape data from our local government. What I want is address from kids adoption offices. Here, in Brazil, all adoptions go through the government. So I have the URL of one office, there are 2 or 3 thousands more. But if I can manage to get one, the others will be easy. I made many attempts, bellow I show three.

The problem could be related to a Javascript (Ajax maybe) that refresh the page.

Note: I am not a PHP developer.

First attempt

echo '<html><head></head><body>';
echo '<h1>Scraper PHP GET 1</h1>';

echo ini_get("allow_url_fopen");
echo ini_get("allow_url_fopen");

// I used this url for test
//$url = 'http://www.portaldaadocao.com.br';

//This is the URL that I really want
$url = 'http://www.cnj.jus.br/cna/Controle/ConsultaPublicaBuscaControle.php?transacao=CONSULTA&vara=2673';

$html = file_get_contents($url);
var_dump($html);

echo '</body></html>';

// Output
// 11
// Warning:
file_get_contents(http://www.cnj.jus.br/cna/Controle/ConsultaPublicaBuscaControle.php?
transacao=CONSULTA&vara=2673) [function.file-get-contents]: failed to open stream: HTTP
request failed! HTTP/1.1 404 Not Found in /home/rsl/www/sc01_get.php on line 14
// bool(false)

Second attempt

echo '<html><head></head><body>';
echo '<h1>Scraper PHP CURL 3</h1>';

// I used this url for test
//$url = 'http://www.portaldaadocao.com.br';

//This is the URL that I really want
$url = 'http://www.cnj.jus.br/cna/Controle/ConsultaPublicaBuscaControle.php?transacao=CONSULTA&vara=2673';

$curl = curl_init($url);
@curl_setopt($curl, CURLOPT_POSTFIELDS, "foo");
@curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
@curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");;

$html=@curl_exec($curl);

if (!$html) {
    echo "<br />cURL error number:" .curl_errno($curl);
    echo "<br />cURL error:" . curl_error($curl);
    exit;
}
else{
   echo '<br>begin HTML[';
    echo $html;
   echo '<br>]end html ';
}
echo '</body></html>';

// Output
// 1

third attempt

function curl($url){
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.6 (KHTML, like Gecko) Chrome/16.0.897.0 Safari/535.6');
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_COOKIEFILE, "cookie.txt");
    curl_setopt($ch, CURLOPT_COOKIEJAR, "cookie.txt");
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
    curl_setopt($ch, CURLOPT_REFERER, "http://www.windowsphone.com");

    $data = curl_exec($ch);
    curl_close($ch);
    return $data;
}

echo '<html><head></head><body>';
echo '<h1>Scraper PHP CURL 5</h1>';

// I used this url for test
//$url = 'http://www.portaldaadocao.com.br';

//This is the URL that I really want
$url = 'http://www.cnj.jus.br/cna/Controle/ConsultaPublicaBuscaControle.php?transacao=CONSULTA&vara=2673';

$curl = curl_init($url);
@curl_setopt($curl, CURLOPT_POSTFIELDS, "foo");
@curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
@curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");;

$html=@curl($curl);

if (!$html) {
    echo "<br />cURL error number:" .curl_errno($curl);
    echo "<br />cURL error:" . curl_error($curl);
    exit;
}
else{
    echo '<br>begin HTML[';
    echo $html;
    echo '<br>]end html ';
}
echo '</body></html>';

// Output
// cURL error number:0
// cURL error:

If the pages are really ajax based meaning the information that you need to scrape is loaded or shown through javascript execution, you will need another approach. You would need to automate with a real browser. You can go the Selenium route which can be written in a number of languages or use CasperJS with Javascript as the programming language.

Source: http://stackoverflow.com/questions/24611046/scraping-data-in-dynamic-sites

Friday, 22 August 2014

Scraping dynamic data

I am scraping profiles on ask.fm for a research question. The problem is that only the top most recent questions are viewable and I have to click "view more" to see the next 15.

The source code for clicking view more looks like this:

<input class="submit-button-more submit-button-more-active" name="commit" onclick="return Forms.More.allowSubmit(this)" type="submit" value="View more" />

What is an easy way of calling this 4 times before scraping it. I want the most recent 60 posts on the site. Python is preferable.

You could probably use selenium to browse to the website and click on the button/link a few times. You can get that here:

    https://pypi.python.org/pypi/selenium

Or you might be able to do it with mechanize:

    http://wwwsearch.sourceforge.net/mechanize/

I have also heard good things about twill, but never used it myself:

    http://twill.idyll.org/

Source: http://stackoverflow.com/questions/19437782/scraping-dynamic-data

Thursday, 21 August 2014

Web Scraping data from different sites

I am looking for a few ideas on how can I solve a design problem I'm going to be faced with building a web scraper to scrape multiple sites. Writing the scraper(s) is not the problem, matching the data from different sites (which may have small differences) is.

For the sake of being generic assume that I am scraping something like this from two or more different sites:

    public class Data {
        public int id;
        public String firstname;
        public String surname;
        ....
    }

If i scrape this from two different sites, I will encounter the situation where I could have the following:

Site A: id=100, firstname=William, surname=Doe

Site B: id=1974, firstname=Bill, surname=Doe

Essentially, I would like to consider these two sets of data the same (they are the same person but with their name slightly different on each site). I am looking for possible design solutions that can handle this.

The only idea I've come up with is scraping the data from a third location and using it as a reference list. Then when I scrape site A or B I can, over time, build up a list of failures and store them in a list for each scraper so that it can know (if i find id=100 then i know that the firstname will be William etc). I can't help but feel this is a rubbish idea!

If you need any more info, or if you think my description is a bit naff, let me know!

Thanks,

DMcB

Source: http://stackoverflow.com/questions/23970057/web-scraping-data-from-different-sites

Wednesday, 20 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

Scraping data from National weather services

Hi I want to get the latest weather data from the link below, meaning the very first row of data, I am trying to scrape the data but have not been successful in doing so. Can anyone please help, or if you know any better way point me to that direction thanks!

this is what i have,

$data = file_get_contents('http://w1.weather.gov/obhistory/KIKV.html');

$regex = '/<td>(.+?) </td>/';

preg_match($regex,$data,$match);

var_dump($match);

echo $match[1];

i get an error on '/(.+?) /' this line that "Unknown modifier 't'" ? Any suggestion

1 Answer

Although parsing html with a regex is usually a very bad idea, the error you are receiving, is caused by the / character. You are using that character as the delimiter for your pattern, so you need to escape it or use another character:

$regex = '/<td>(.+?) <\/td>/';

or

$regex = '#<td>(.+?) </td>#';

Source:http://stackoverflow.com/questions/11943420/scraping-data-from-national-weather-services

Friday, 1 August 2014

Importance of Data Cleansing Services

In companies, there is huge amount of data that is available and essential in the decision making and strategies. Unfortunately, the data is sometimes inaccurate or incomplete because of the updates that are available from time to time. With this, companies are looking for ways to eradicate the information that is not needed by the company. Cleansing of data is one of the processes that can eliminate unnecessary data of the companies. Data cleansing identifies the information that is fraudulent or inaccurate and deletes them or replaces them with the accurate information. Unclean facts have no place in companies because they can also cause inefficiencies and inaccuracies in the decisions. After the cleaning of data, there are no inconsistencies and the data sets are already the same with each other.

There are different techniques used in data cleansing data transformation, parsing or detecting the syntax errors, duplicate eradication, and statistical method. These techniques will ensure that the data are clean and good. There are also criteria to tell if the data set is clean. This are the things that companies look for when getting data cleansing services.

Data should be accurate in which density, integrity, and consistency are there. They should also be complete in order to ensure that there are no differences in the data set. The density will show the relationship of the omitted and the total number of values in the data set. You can tell that the data set is good if it has a good density. Data should also be uniform and the irregularities should be eliminated in the set. Consistency should also be present that eliminates the syntactical errors in the set. Cleaning the data should also give the uniqueness of the set in order to tell the number of duplicates that were present before the cleaning. Lastly, the data should have integrity in combining the criteria of soundness and completeness. If the above criteria are met, it is ensured that the data set is in the best state.

Considering in getting a data cleansing service will offer you different available services. Removal of duplicate ideas is one of the most common features of data cleansing. Same records or data sets are tagged and identified and the duplicates are eradicated. Data are also validated and the bogus data are eliminated. The set will also be checked for outdated data because outdated ones are removed by data cleansing. Incomplete figures are also identified so that they will be given attention. If the incomplete data are identified, the facts will be improved in such a way that they are assembled in order and organized as a set.

Aside from the benefits that companies get from data cleansing services, there are also problems present in data cleansing. Sometimes, some data are lost because of the eradication of limited information. As for the companies that offer the services, they should maintain good service since data cleansing is expensive and time consuming.

Source:http://ezinearticles.com/?Importance-of-Data-Cleansing-Services&id=5013611