Issues downloading full HTML of webpage with Python - python

I'm working on a project where I require the all of the game ID #'s found in the current scores section of http://www.nhl.com/ to download content/ parse stats for each game. I want to be able to get all current game ID's in one go, but for some reason, I'm unable to download the full HTML of the page, no matter how I try. I'm using requests and beautifulsoup4.
Here's my problem:
I've determined that the particular tags I'm interested in are div's where the CSS class = 'scrblk'. So, I wrote a function to pass into BeautifulSoup.find_all() to give me, specifically, blocks with that CSS class. It looks like this:
def find_scrblk(css_class):
return css_class is not None and css_class == 'scrblk'
so, when I actually went to the web page in Firefox and saved it, then loaded the saved file in beautifulsoup4, I did the following:
>>>soup = bs(open('nhl.html'))
>>>soup.find_all(class_=find_scrblk)
[<div class="scrblk" id="hsb2015010029"> <div class="defaultState"....]
and everything was all fine and dandy; I had all the info I needed. However, when I tried to download the page using any of several automated methods I know, this returned simply an empty list. Here's what I tried:
using requests.get() and saving the .text attribute in a file
using the iter_content() and iter_lines() methods of the request
object to write to the file piece by piece
using wget to download the page (through subprocess.call())
and open the resultant file. For this option, I was sure to use the --page-requisites and --convert-links flags so I downloaded (or so I thought)
all the necessary data.
With all of the above, I was unable to parse out the data that I need from the HTML files; it's as if they weren't being completely downloaded or something, but I have no idea what that something is or how to fix it. What am I doing wrong or missing here? I'm using python 2.7.9 on Ubuntu 15.04.
All of the files can be downloaded here:
https://www.dropbox.com/s/k6vv8hcxbkwy32b/nhl_html_examples.zip?dl=0

As the comments on your question state, you have to re-think your approach. What you see in the browser is not what the response contains. The site uses JavaScript to load the information you are after so you should look more carefully in the result what you get to find what you are looking for.
In the future to handle such problems try out Chrome's developer console and disable JavaScript and open a site such way. Then you will see if you are facing JS or the site would contain the values you are looking for.
And by the way what you do is against the Terms of Service of the NHL website (according to Section 2. Prohibited Content and Activities)
Engage in unauthorized spidering, scraping, or harvesting of content or information, or use any other unauthorized automated means to compile information;

Related

The HTML code I scrape seems to be incomplete in comparison to the full website. Could the HTML be changing dynamically?

I am currently scraping a website for work to be able to sort the data locally, however when I do this the code seems to be incomplete, and I feel may be changing whilst I scroll on the website to add more content. Can this happen ? And if so, how can I ensure I am able to scrape the whole website for processing?
I only currently know some python and html for web scraping, looking into what other elements may be affecting this issue (javascript or ReactJS etc).
I am expecting to get a list of 50 names when scraping the website, but it only returns 13. I have downloaded the whole HTML file to go through it and none of the other names seem to exist in the file, i.e. why I think the file may be changing dynamically
Yes, the content of the HTML can be dynamic, and Javascript loading should be the most essential . For Python, scrapy+splash maybe a good choice to get started.
Depending on how the data is handled, you can have different methods to handle dyamic content HTML

Script cannot fetch data from a web page

I am trying to write a program in Python that can take the name of a stock and its price and print it. However, when I run it, nothing is printed. it seems like the data is having a problem being fetched from the website. I double checked that the path from the web page is correct, but for some reason the text does not want to show up.
from lxml import html
import requests
page = requests.get('https://www.bloomberg.com/quote/UKX:IND?in_source=topQuotes')
tree = html.fromstring(page.content)
Prices = tree.xpath('//span[#class="priceText__1853e8a5"]/text()')
print ('Prices:' , Prices)
here is the website I am trying to get the data from
I have tried BeautifulSoup, but it has the same problem.
If you print the string page.content, you'll see that the website code it captures is actually for a captcha test, not the "real" destination page itself you see when you manually visit the website. It seems that the website was smart enough to see that your request to this URL was from a script and not manually from a human, and it effectively prevented your script from scraping any real content. So Prices is empty because there simply isn't a span tag of class "priceText__1853e8a5" on this special Captcha page. I get the same when I try scraping with urllib2.
As others have suggested, Selenium (actual web automation) might be able to launch the page and get you what you need. The ID looks dynamically generated, though I do get the same one when I manually look at the page. Another alternative is to simply find a different site that can give you the quote you need without blocking your script. I tried it with https://tradingeconomics.com/ukx:ind and that works. Though of course you'll need a different xpath to find the cell you need.

How to get renewable information on a web by python3?

I want to get some information on a web page. I use requests.get to abstract the page. But I cannot find what I want. Checking it carefully, I found the info I want is in a list with a scrollbar. When I drag scrollbar down, more and more info is loaded. So I guess all the info in the list is not loaded yet when I get the page by module requests. I want to know what is happened in this process and How can I gather the information I want. (I am not familiar with Html language).
I want to know what is happened in this process
It sounds like when the user scrolls, the scrolling causes some javascript(js) to execute, and the js makes repeated requests to the server for more data. Unfortunately, the requests module cannot cause the javascript on an html page to execute--all you get back is the text of the js. The unable to execute javascript on an html page in order to retrieve what the user actually sees has been a problem for a long time. Fortunately, smart programmers have largely solved that problem. You need to use a different module. Check out the selenium module.
I am not familiar with Html language
Scraping web pages can get really tricky really fast, and some web pages proactively try to prevent computer programs from scraping their content, so you need to know both html and js in order to figure out what is going on.

How to scrape AJAX website?

In the past, I've used the urllib2 library to get source codes from websites. However, I've noticed that for a recent website I've been trying to play with, I can't find the information I need in the source code.
http://www.wgci.com/playlist is the site that I've been looking at, and I want to get the most recently played song and the playlist of recent songs. I essentially want to copy and paste the visible, displayed text on a website and put it in a string. Alternatively, being able to access the element that holds these values in plaintext and get them using urllib2 normally would be nice. Is there anyway to do either of these things?
Thanks kindly.
The website you want to scrap is using ajax calls to populate it's pages with data.
You have 2 ways to scrapping data from it:
Use a headless browser that supports javascript (ZombieJS for instance), and scrap the generated output, but that's complicated and overkill
Understand how their API work, and call that directly, which is way simpler.
Use Chrome dev tools (network tab) to see the calls while browsing their website.
For example, the list of last played songs for a given stream is available in JSON at
http://www.wgci.com/services/now_playing.html?streamId=841&limit=12

Unable to find exact source code of my blog

I am into a project where I deal with parsing HTML of web pages. So, I took my blog (Bloggers Blog - Dynamic Template) and tried to read the content of it. Unfortunately I failed to look at "actual" source of the blog's webpage.
Here is what I observed:
I clicked view source on a random article of my blog and tried to find the content in it. and I couldn't find any. It was all JavaScript.
So, I saved the webpage to my laptop and checked the source again, this time I found the content.
I also checked the source using developers tools in browsers and again found the content in it.
Now, I tried the python way
import urllib
from bs4 import BeautifulSoup
soup = BeautifulSoup( urllib.urlopen("my-webpage-address") )
print soup.prettify()
I even didn't find the content in the HTML code in it.
Finally, why I am unable to find the content in the source code in case1, 4.
How should I get the actual HTML code? I wish to hear any python library that would do the job.
The content is loaded via JavaScript (AJAX). It's not in the "source".
In step 2, you are saving the resulting page, not the original source. In step 3, you're seeing what's being rendered by the browser.
Steps 1 and 4 "don't work" because you're getting the page's source (which doesn't contain the content). You need to actually run the JavaScript, which isn't easy for a screen scraper to do.

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