Web scraping for dummies (or not) - python

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

Related

Python scraping dynamic table

I tried with several different attempts to scrape the following page:
https://www.finanzen.ch/rohstoffe/historisch/weizenpreis/euro/17.4.2022_17.5.2022
Somehow, I'm not successful with request or selenium approach.
Those anybody has an idea how to scrape the data of the historical data table?
Thanks for your hints.
ThinkerBell
You can't bypass this website using simple requests.get, selenium/splash and even rotating-proxies won't work always. This is because, this website uses "Captcha services" and it knows how you are trying to access the page. The headers contains "Content-Disposition: form-data; name='recaptcha-token';" with a long cipher/encoded term, and since this term is based on your browsing activities, copy-pasting it in headers won't work either.
For such tricky websites, best option is to use browser based add-ons like "iMacro". You may also increase chances through Selenium, if you start browsing homepage and loading few more dummy links, before reaching the targeted link.

How to scrape a website and all its directories from the one link?

Sorry if this is not a valid question, i personally feel it kind of boarders on the edge.
Assuming the website involved has given full permission
How could I download the ENTIRE contents (html) of that website using a python data scraper. By entire contents I refer to not only the current page you are on, but any other directory that branches off of that main website. Eg.
Using the link:
https://www.dogs.com
could I pull info from:
https://www.dogs.com/about-us
and any other directory attached to the "https://www.dogs.com/"
(I have no idea is dogs.com is a real website or not, just an example)
I have already made a scraper that will pull info from a certain link (nothing further than that), but I want to further improve it so I dont have to have heaps of links. I understand I can use an API but if this is possible I would rather this. Cheers!
while there is scrapy to do it professionally, you can use requests to get the url data, and bs4 to parse the html and look into it. it's also easier to do for a beginner i guess.
anyhow you go, you need to have a starting point, then you just follow the link's in the page, and then link's within those pages.
you might need to check if the url is linking to another website or is still in the targeted website. find the pages one by one and scrape them.

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.)

transferring real time data from a website in 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.

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