urllib2 not returning full webpage - python

I'm just starting out in Python and I'm trying to request the html source code of a site using urllib2. However when I try and get the html content from a site I'm not getting the full html content - there are tags missing. I know they're missing as when I view the site in firebug the code shows up. Is this due to the way I'm requesting the data - or due to the site? If so is there a way in which I can get the full source code of the site in python, and then parse it?
Currently the code I'm using to request the content and the site I'm trying is:
import urllib2
url = 'http://marinetraffic.com/ais/'
response = urllib2.urlopen(url)
html = response.read()
print(html)
Specifically the content between the - div id="map_area" - is missing. Any help/pointers greatly appreciated!

You are getting incomplete data because most of the content on this page is dynamically generated via Javascript...

read on a descriptor returned by urlopen will only return what has already been downloaded. So you're liable to get a short read. You're better off using urllib.urlretrieve(), which tries to fetch the entire file, checks the Content-Length header, and raises an error if it fails.

Related

scraping inside script tag with beautifulsoup

I'm scraping data from e-commerce site and I need model number of each laptops. But in div tags, there are no model numbers. I found model number inside script tag as "productCode". For this example its:
"productCode":"MGND3TU/A"
How can I gather the "productCode" data. I couldn't understand from other posts.
Edit: I find the ‘productCode’ inside script tag. But i don’t know how to get it. You can check from page source.
Since the JSON is hidden in the <head>, it can be parsed, but with some custom logic.
Unfortunately the script tags exports the JSON to a window var, so we'll need to remove that befor we can parse it.
Get url
Get all <script>
Check if PRODUCT_DETAIL_APP_INITIAL_STAT exist in the string (valid json)
Remove the prefix (hardcoded)
Find the index of the next key (hardcoded)
Remove after the suffix
Try to parse to json
Print json['product']['productCode'] if it exists
import json
from urllib.request import urlopen
from bs4 import BeautifulSoup
import requests
reqs = requests.get("https://www.trendyol.com/apple/macbook-air-13-m1-8gb-256gb-ssd-altin-p-67940132")
soup = BeautifulSoup(reqs.text, 'html.parser')
for sc in soup.findAll('script'):
if len(sc.contents) > 0 and "PRODUCT_DETAIL_APP_INITIAL_STAT" in sc.contents[0]:
withoutBegin = sc.contents[0][44:]
endIndex = withoutBegin.find('window.TYPageName=') - 1
withoutEnd = withoutBegin[:endIndex]
try:
j = json.loads(withoutEnd)
if j['product']['productCode']:
print(j['product']['productCode'])
except Exception as e:
print("Unable to parse JSON")
continue
Output:
MGND3TU/A
In this case beautifulsoup is not needed cause response could be searched directly with regex:
json.loads(re.search(r"window.__PRODUCT_DETAIL_APP_INITIAL_STATE__=({.*}});window", r).group(1))
Example
import requests, re, json
r = requests.get('https://www.trendyol.com/apple/macbook-air-13-m1-8gb-256gb-ssd-altin-p-67940132').text
json_data = json.loads(re.search(r"window.__PRODUCT_DETAIL_APP_INITIAL_STATE__=({.*}});window", r).group(1))
json_data['product']['productCode']
Output
MGND3TU/A
That's because those tags are generated using JavaScript. When you send a request to that URL, you will get back a response which has information for a JS script to build DOM for you. (technically JSON information):
To see what your returned response actually is, either print the value of r.text (r is returned from requests.get()) or manually see the "view page source" from the browser. (not inspect element section)
Now to solve it, you can either use something that can render JS, just like your browser. For example Selenium. requests module is not capable of rendering JS. It is just for sending and receiving requests.
Or manually extract that JSON text from the returned text (using Regex or,...) then create a Python dictionary from it.

How do I fix fix getting "None" as a response when web scraping?

So I am trying to create a small code that gets the views from a youtube video and prints them. However using this code when printing the text var I just get the response "None". Is there a way to get a response of the actual view count using these libraries?
import requests
from bs4 import BeautifulSoup
url = requests.get("https://www.youtube.com/watch?v=dQw4w9WgXcQ")
soup = BeautifulSoup(url.text, 'html.parser')
text = soup.find('span', {'class': "view-count style-scopeytd-video-view-count-renderer"})
print(text)
To see why, you should use wget or curl to fetch a copy of that page and look at it, or use "view source" from your browser. That's what requests sees. None of those classes appear in the HTML you get back. That's why you get None -- because there ARE none.
YouTube builds all of its pages dynamically, through Javascript. requests doesn't interpret Javascript. If you need to do this, you'll need to use something like Selenium to run a real browser with a Javascript interpreter built in.

Python Requests Library - Scraping separate JSON and HTML responses from POST request

I'm new to web scraping, programming, and StackOverflow, so I'll try to phrase things as clearly as I can.
I'm using the Python requests library to try to scrape some info from a local movie theatre chain. When I look at the Chrome developer tools response/preview tabs in the network section, I can see what appears to be very clean and useful JSON:
However, when I try to use requests to obtain this same info, instead I get the entire page content (pages upon pages of html). Upon further inspection of the cascade in the Chrome developer tools, I can see there are two events called GetNowPlayingByCity: One contains the JSON info while the other seems to be the HTML.
JSON Response
HTML Response
How can I separate the two and only obtain the JSON response using the Python requests library?
I have already tried modifying the headers within requests.post (the Chrome developer tools indicate this is a post method) to include "accept: application/json, text/plain, */*" but didn't see a difference in the response I was getting with requests.post. As it stands I can't parse any JSON from the response I get with requests.post and get the following error:
"json.decoder.JSONDecodeError: Expecting value: line 4 column 1 (char 3)"
I can always try to parse the full HTML, but it's so long and complex I would much rather work with friendly JSON info. Any help would be much appreciated!
This is probably because the javascript the page sends to your browser is making a request to an API to get the json info about the movies.
You could either try sending the request directly to their API (see edit 2), parse the html with a library like Beautiful Soup or you can use a dedicated scraping library in python. I've had great experiences with scrapy. It is much faster than requests
Edit:
If the page uses dynamically loaded content, which I think is the case, you'd have to use selenium with the PhantomJS browser instead of requests. here is an example:
from bs4 import BeautifulSoup
from selenium import webdriver
url = "your url"
browser = webdriver.PhantomJS()
browser.get(url)
html = browser.page_source
soup = BeautifulSoup(html, 'lxml')
# Then parse the html code here
Or you could load the dynamic content with scrapy
I recommend the latter if you want to get into scraping. It would take a bit more time to learn but it is a better solution.
Edit 2:
To make a request directly to their api you can just reproduce the request you see. Using google chrome, you can see the request if you click on it and go to 'Headers':
After that, you simply reproduce the request using the requests library:
import requests
import json
url = 'http://paste.the.url/?here='
response = requests.get(url)
content = response.content
# in my case content was byte string
# (it looks like b'data' instead of 'data' when you print it)
# if this is you case, convert it to string, like so
content_string = content.decode()
content_json = json.loads(content_string)
# do whatever you like with the data
You can modify the url as you see fit, for example if it is something like http://api.movies.com/?page=1&movietype=3 you could modify movietype=3 to movietype=2 to see a different type of movie, etc

How to take table data from a website using bs4

I'm trying to scrape a website that has a table in it using bs4, but the element of the content I'm getting is not as complete compared to the one I get from inspect. I cannot find the tag <tr> and <td> in it. How can I get the full content of that site especially the tags for the table?
Here's my code:
from bs4 import BeautifulSoup
import requests
link = requests.get("https://pemilu2019.kpu.go.id/#/ppwp/hitung-suara/", verify = False)
src = link.content
soup = BeautifulSoup(src, "html.parser")
print(soup)
I expect the content to have the tag <tr> and <td> in it because they do exist when I inspect it,but I found none from the output.
Here's the image of the page where there is the tag <tr> and <td>
You should dump the contents of the text you're trying to parse to a file and look at it. This will tell you for sure what is and isn't there. Like this:
from bs4 import BeautifulSoup
import requests
link = requests.get("https://pemilu2019.kpu.go.id/#/ppwp/hitung-suara/", verify = False)
src = link.content
with open("/tmp/content.html", "w") as f:
f.write(src)
soup = BeautifulSoup(src, "html.parser")
print(soup)
Run this code, and then look at the file "/tmp/content.html" (use a different path, obviously, if you're on Windows), and look at what is actually in the file. You could probably do this with your browser, but this this is the way to be the most sure you know what you are getting. You could, of course, also just add print(src), but if it were me, I'd dump it to a file
If the HTML you're looking for is not in the initial HTML that you're getting back, then that HTML is coming from somewhere else. The table could be being built dynamically by JavaScript, or coming from another URL reference, possibly one that calls an HTTP API to grab the table's HTML via parameters passed to the API endpoint.
You will have to reverse engineer the site's design to find where that HTML comes from. If it comes from JavaScript, you may be stuck short of scripting the execution of a browser so you can gain access programmatically to the DOM in the browser's memory.
I would recommend running a debugging proxy that will show you each HTTP request being made by your browser. You'll be able to see the contents of each request and response. If you can do this, you can find the URL that actually returns the content you're looking for, if such a URL exists. You'll have to deal with SSL certificates and such because this is a https endpoint. Debugging proxies usually make that pretty easy. We use Charles. The standard browser toolboxes might do this too...allow you to see each request and response that is generated by a particular page load.
If you can discover the URL that actually returns the table HTML, then you can use that URL to grab it and parse it with BS.

Invalid Argument in Open method for web scraping

I am trying to scrape some data from the ancestry, I have a .net background but thought i'd try a bit of python for a project.
I'm falling at the first step, Firstly i am trying to open this page and then just print out the rows.
from requests import get
from requests.exceptions import RequestException
from contextlib import closing
from bs4 import BeautifulSoup
raw_html = open('https://www.ancestry.co.uk/search/collections/britisharmyservice/?
birth=_merthyr+tydfil-wales-united+kingdom_1651442').read()
html = BeautifulSoup(raw_html, 'html.parser')
for p in html.select('tblrow record'):
print(p)
I am getting an illegal argument on open.
According to documentation, open is used to:
Open [a] file and return a corresponding file object.
As such, you cannot use it for downloading the HTML contents of a webpage. You probably meant to use requests.get as follows:
raw_html = get('https://www.ancestry.co.uk/search/collections/britisharmyservice/?
birth=_merthyr+tydfil-wales-united+kingdom_1651442').text
# .text gets the raw text of the response
# (http://docs.python-requests.org/en/master/api/#requests.Response.text)
Here are a few recommendation to improve your code as well:
requests.get provides many useful parameters, one of them being params, which allows you to provide the URL parameters in the form of a Python dictionary.
If you need to verify whether the request was successful before accessing its text, then just check if the returned response.status_code == requests.codes.ok. This only covers status code 200, but if you need more codes, then response.raise_for_status should be helpful.

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