Monday, 25 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

What is the right way of storing screen-scraping data?

i'm working on a web site. it is scraping product details(names, features, prices etc.) from various web sites, processing and displaying them. i'am considering to run update script on each day and keep data fresh.

    scrape data
    process them
    store on database
    read(from db) and display them

i'am already storing all the data in a sql schema but i'm not sure. After each update, all the old records are vanishing. if the scraped new data comes corrupted somehow, there is nothing to show.

so, is there any common way to archive the old data? which one is more convenient: seperate sql schemas or xml files? or something else?

Source: http://stackoverflow.com/questions/13686474/what-is-the-right-way-of-storing-screen-scraping-data

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

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

Monday, 18 August 2014

Has It Been Done Before? Optimize Your Patent Search Using Patent Scraping Technology

Has it been done before? Optimize your Patent Search using Patent Scraping Technology.

Since the US patent office opened in 1790, inventors across the United States have been submitting all sorts of great products and half-baked ideas to their database. Nowadays, many individuals get ideas for great products only to have the patent office do a patent search and tell them that their ideas have already been patented by someone else! Herin lies a question: How do I perform a patent search to find out if my invention has already been patented before I invest time and money into developing it?

The US patent office patent search database is available to anyone with internet access.

US Patent Search Homepage


Performing a patent search with the patent searching tools on the US Patent office webpage can prove to be a very time consuming process. For example, patent searching the database for "dog" and "food" yields 5745 patent search results. The straight-forward approach to investigating the patent search results for your particular idea is to go through all 5745 results one at a time looking for yours. Get some munchies and settle in, this could take a while! The patent search database sorts results by patent number instead of relevancy. This means that if your idea was recently patented, you will find it near the top but if it wasn't, you could be searching for quite a while. Also, most patent search results have images associated with them. Downloading and displaying these images over the internet can be very time consuming depending on you internet connection and the availability of the patent search database servers.

Because patent searches take such a long time, many companies and organizations are looking ways to improve the process. Some organizations and companies will hire employees for the sole purpose of performing patent searches for them. Others contract out the job to small business that specialize in patent searches. The latest technology for performing patent searches is called patent scraping.

Patent scraping is the process of writing computer automated scripts that analyze a website and copy only the content you are interested in into easily accessible databases or spreadsheets on your computer. Because it is a computerized script performing the patent search, you don't need a separate employee to get the data, you can let it run the patent scraping while you perform other important tasks! Patent scraping technology can also extract text content from images. By saving the images and textual content to your computer, you can then very efficiently search them for content and relevancy; thus saving you lots of time that could be better spent actually inventing something!

To put a real-world face on this, let us consider the pharmaceutical industry. Many different companies are competing for the patent on the next big drug. It has become an indispensible tactic of the industry for one company to perform patent searches for what patents the other companies are applying for, thus learning in which direction the research and development team of the other company is taking them. Using this information, the company can then choose to either pursue that direction heavily, or spin off in a different direction. It would quickly become very costly to maintain a team of researchers dedicated to only performing patent searches all day. Patent scraping technology is the means for figuring out what ideas and technologies are coming about before they make headline news. It is by utilizing patent scraping technology that the large companies stay up to date on the latest trends in technology.

While some companies choose to hire their own programming team to do their patent scraping scripts for them, it is much more cost effective to contract out the job to a qualified team of programmers dedicated to performing such services.

Source:http://ezinearticles.com/?Has-It-Been-Done-Before?-Optimize-Your-Patent-Search-Using-Patent-Scraping-Technology&id=171000

Tuesday, 12 August 2014

How Your Online Information is Stolen - The Art of Web Scraping and Data Harvesting

Web scraping, also known as web/internet harvesting involves the use of a computer program which is able to extract data from another program's display output. The main difference between standard parsing and web scraping is that in it, the output being scraped is meant for display to its human viewers instead of simply input to another program.

Therefore, it isn't generally document or structured for practical parsing. Generally web scraping will require that binary data be ignored - this usually means multimedia data or images - and then formatting the pieces that will confuse the desired goal - the text data. This means that in actually, optical character recognition software is a form of visual web scraper.

Usually a transfer of data occurring between two programs would utilize data structures designed to be processed automatically by computers, saving people from having to do this tedious job themselves. This usually involves formats and protocols with rigid structures that are therefore easy to parse, well documented, compact, and function to minimize duplication and ambiguity. In fact, they are so "computer-based" that they are generally not even readable by humans.

If human readability is desired, then the only automated way to accomplish this kind of a data transfer is by way of web scraping. At first, this was practiced in order to read the text data from the display screen of a computer. It was usually accomplished by reading the memory of the terminal via its auxiliary port, or through a connection between one computer's output port and another computer's input port.

It has therefore become a kind of way to parse the HTML text of web pages. The web scraping program is designed to process the text data that is of interest to the human reader, while identifying and removing any unwanted data, images, and formatting for the web design.

Though web scraping is often done for ethical reasons, it is frequently performed in order to swipe the data of "value" from another person or organization's website in order to apply it to someone else's - or to sabotage the original text altogether. Many efforts are now being put into place by webmasters in order to prevent this form of theft and vandalism.

Source:http://ezinearticles.com/?How-Your-Online-Information-is-Stolen---The-Art-of-Web-Scraping-and-Data-Harvesting&id=923976