transferring real time data from a website in python - python

I am programming in Python.
I would like to extract real time data from a webpage without refreshing it:
http://www.fxstreet.com/rates-charts/currency-rates/
I think the real time data webpage is written in AJAX but I am not quite sure..
I thought about opening an internet browser with the program but I do not really know/like this way... Is there an other way to do it?
I would like to fill a dictionnary in my program (or even a SQL database) with the latest numbers each second.
please help me in python, thanks!

To get the data, you'll need to look through the javascript and HTML source to find what URL it's hitting to get the data it's displaying. Then, you can call that URL with urllib or your favorite python library and parse it
Also, it may be easier if you use a plugin like Firebug that lets you watch the AJAX requests.

Related

Web scraping for dummies (or not)

GOAL
Extract data from a web page.. automatically.
Data are on this page... Be careful , it's in French...
MY HARD WAY, manually
I choose the data I want by clicking on the desired fields on the left side ('CHOISIR DES INDICATEURS')
Then I select ('Tableau' = Table), to have data table.
Then I click on ('Action'), on the right side, then ('Exporter' = Export)
I choose the format I want (ie CSV) and hit ('Executer'= Execute) to download the file.
WHAT I TRIED
I tried to automate this process, but It's like an impossible task for me. I tried to inspect the page for the network exchanges to see if there is an underlying server I could make easy json request.
I mainly work with python and frameworks like BS4 or scrapy.
I have few data to extract, so I can easily do it manually. Thus this question, I just purely for my own knowledge, to see if it is possible to scrape a page like that.
I would appreciate if you could share your skills!
Thank you,
It is possible. Check this website for details. This website will tell you how to scrape a website with an example.
https://realpython.com/beautiful-soup-web-scraper-python/#scraping-the-monster-job-site

How to automate pulling data (KMZ? JSON?) from My Google Maps

Seeking a bit of guidance on a general approach as to how one would automate the retrieval of data from a My Google Map. While I could easily export any given layer to KML/KMZ, I'm looking for a way to do this within a larger script, that will automate the process. Preferably, where I wouldn't even have to log in to the map itself to complete the data pull.
So, what do you think the best approach is? Two possible options I'm considering are 1) using selenium/beautiful soup to simulate page-clicks on Google Maps and export the KMZ or 2) making use of Python Google Maps API. Though, I'm not sure if this API makes it possible to download Google Maps layer via a script.
To be clear, the data is already in the map - I'm just looking for a way to export it. It could either be a KMZ export, or better yet, GeoJSON.
Any thoughts or advice welcome! Thank you in advance.
I used my browser’s inspection feature to figure out what was going on under the hood with the website I was interested in grabbing data from, which led me to this solution.
I use Selenium to login and navigate said website, then transfer my cookies to Python’s Requests package. I have Requests send a specific query to the server whose response is in the form of JSON. I was able to figure out what query to send and what form the response would be through the inspection feature previously stated. Once I have the response in JSON I use Python’s JSON package to convert into a Python dict to use however I need.
Sounds like you might not necessarily need Selenium but it does sound like the Requests package would be useful to your use case. I think your first step is figuring out what form the server response is when you interact with the website naturally to get what you want.
Hopefully this helps to some degree!

How can i convert scraping script as web-service?

I want to build a api that accepts a string and returns html code.
Here is my scraping code that i want as a web-service.
Code
from selenium import webdriver
import bs4
import requests
import time
url = "https://www.pnrconverter.com/"
browser = webdriver.Firefox()
browser.get(url)
string = "3 PS 232 M 03FEB 7 JFKKBP HK2 1230A 420P 03FEB E
PS/JPIX8U"
button =
browser.find_element_by_xpath("//textarea[#class='dataInputChild']")
button.send_keys(string) #accept string
button.submit()
time.sleep(5)
soup = bs4.BeautifulSoup(browser.page_source,'html.parser')
html = soup.find('div',class_="main-content") #returns html
print(html)
Can anyone tell me the best possible solution to wrap up my code as a api/web-service.
There's no best possible solution in general, because a solution has to fit the problem and the available resources.
Right now it seems like you're trying to wrap someone else's website. If that's the problem you're actually trying to solve, and you want to give credit, you should probably just forward people to their site. Have your site return a 302 Redirect with their URL in the Location field in your header.
If what you're trying to do is get the response from this one sample check you have hardcoded, and and make that result available, I would suggest you put it in a static file behind nginx.
If what you're trying to do is use their backend to turn itineraries you have into responses you can return, you can do that by using their backend API, once that becomes available. Read the documentation, use the requests library to hit the API endpoint that you want, and get the JSON result back, and format it to your desires.
If you're trying to duplicate their site by making yourself a man-in-the-middle, that may be illegal and you should reconsider what you're doing.
For hosting purposes, you need to figure out how often your API will be hit. You can probably start on Heroku or something similar fairly easily, and scale up if you need to. You'll probably want WebObj or Flask or something similar sitting at the website where you intend to host this application. You can use those to process what I presume will be a simple request into the string you wish to hit their API with.
I am the owner of PNR Converter, so I can shed some light on your attempt to scrape content from our site. Unfortunately scraping from PNR Converter is not recommended. We are developing an API which looks like it would suit your needs, and should be ready in the not too distant future. If you contact us through the site we would be happy to work with you should you wish to use PNR Converter legitimately. PNR Converter gets at least one complete update per year and as such we change all the code on a regular basis. We also monitor all requests to our site, and we will block any requests which are deemed as improper usage. Our filter has already picked up your IP address (ends in 250.144) as potential misuse.
Like I said, should you wish to work with us at PNR Converter legitimately and not scrape our content then we would be happy to do so! please keep checking https://www.pnrconverter.com/api-introduction for information relating to our API.
We are releasing a backend upgrade this weekend, which will have a different HTML structure, and dynamically named elements which will cause a serious issue for web scrapers!

How to read a HTML page that takes some time to load? [duplicate]

I am trying to scrape a web site using python and beautiful soup. I encountered that in some sites, the image links although seen on the browser is cannot be seen in the source code. However on using Chrome Inspect or Fiddler, we can see the the corresponding codes.
What I see in the source code is:
<div id="cntnt"></div>
But on Chrome Inspect, I can see a whole bunch of HTML\CSS code generated within this div class. Is there a way to load the generated content also within python? I am using the regular urllib in python and I am able to get the source but without the generated part.
I am not a web developer hence I am not able to express the behaviour in better terms. Please feel free to clarify if my question seems vague !
You need JavaScript Engine to parse and run JavaScript code inside the page.
There are a bunch of headless browsers that can help you
http://code.google.com/p/spynner/
http://phantomjs.org/
http://zombie.labnotes.org/
http://github.com/ryanpetrello/python-zombie
http://jeanphix.me/Ghost.py/
http://webscraping.com/blog/Scraping-JavaScript-webpages-with-webkit/
The Content of the website may be generated after load via javascript, In order to obtain the generated script via python refer to this answer
A regular scraper gets just the HTML document. To get any content generated by JavaScript logic, you rather need a Headless browser that would also generate the DOM, load and run the scripts like a regular browser would. The Wikipedia article and some other pages on the Net have lists of those and their capabilities.
Keep in mind when choosing that some previously major products of those are abandoned now.
TRY THIS FIRST!
Perhaps the data technically could be in the javascript itself and all this javascript engine business is needed. (Some GREAT links here!)
But from experience, my first guess is that the JS is pulling the data in via an ajax request. If you can get your program simulate that, you'll probably get everything you need handed right to you without any tedious parsing/executing/scraping involved!
It will take a little detective work though. I suggest turning on your network traffic logger (such as "Web Developer Toolbar" in Firefox) and then visiting the site. Focus your attention attention on any/all XmlHTTPRequests. The data you need should be found somewhere in one of these responses, probably in the middle of some JSON text.
Now, see if you can re-create that request and get the data directly. (NOTE: You may have to set the User-Agent of your request so the server thinks you're a "real" web browser.)

Parsing from a website -- source code does not contain the info I need

I'm a little new to web crawlers and such, though I've been programming for a year already. So please bear with me as I try to explain my problem here.
I'm parsing info from Yahoo! News, and I've managed to get most of what I want, but there's a little portion that has stumped me.
For example: http://news.yahoo.com/record-nm-blaze-test-forest-management-225730172.html
I want to get the numbers beside the thumbs up and thumbs down icons in the comments. When I use "Inspect Element" in my Chrome browser, I can clearly see the things that I have to look for - namely, an em tag under the div class 'ugccmt-rate'. However, I'm not able to find this in my python program. In trying to track down the root of the problem, I clicked to view source of the page, and it seems that this tag is not there. Do you guys know how I should approach this problem? Does this have something to do with the javascript on the page that displays the info only after it runs? I'd appreciate some pointers in the right direction.
Thanks.
The page is being generated via JavaScript.
Check if there is a mobile version of the website first. If not, check for any APIs or RSS/Atom feeds. If there's nothing else, you'll either have to manually figure out what the JavaScript is loading and from where, or use Selenium to automate a browser that renders the JavaScript for you for parsing.
Using the Web Console in Firefox you can pretty easily see what requests the page is actually making as it runs its scripts, and figure out what URI returns the data you want. Then you can request that URI directly in your Python script and tease the data out of it. It is probably in a format that Python already has a library to parse, such as JSON.
Yahoo! may have some stuff on their server side to try to prevent you from accessing these data files in a script, such as checking the browser (user-agent header), cookies, or referrer. These can all be faked with enough perseverance, but you should take their existence as a sign that you should tread lightly. (They may also limit the number of requests you can make in a given time period, which is impossible to get around.)

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