Crawl and download files from informer.com using python script

Question

For research purpose, I need to build a set of benign programs. First, I need to get these programs from http://downloads.informer.com. To do so, I have written a python script that iterates each downloading page and extract the download links into a list. After that the script uses these links to download the programs (these programs are exe, msi, or zip files). Unfortunately, at this step, the script runs into error stating that (AttributeError: 'Request' object has no attribute 'decode').

Following is the script that works on single page and retrieves single program (for simplicity):

import wget
from urllib.request import urlopen as uReq
from bs4 import BeautifulSoup as soup
my_url = 'http://sweet-home-3d.informer.com/download'

import urllib.request
req = urllib.request.Request(
    my_url, 
    data=None, 
    headers={
        'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.47 Safari/537.36'
    }
)


uClient = uReq(req)
page_html = uClient.read()

page_soup = soup(page_html, 'lxml' )

cont01 = page_soup.findAll('a', {'class':'download_button'})

conts = cont01[1]
ref= conts['href']

addr = urllib.request.Request(
    ref, 
    data=None, 
    headers={
        'User-Agent': 'Mozilla/5.0'
    }
)
wget.download(addr)

The error I get is following:

AttributeError                            Traceback (most recent call last)
<ipython-input-1-93c4caaa1777> in <module>()
     31     }
     32 )
---> 33 wget.download(addr)

C:\Users\bander\Anaconda3\lib\site-packages\wget.py in download(url, out, bar)
    503 
    504     # get filename for temp file in current directory
--> 505     prefix = detect_filename(url, out)
    506     (fd, tmpfile) = tempfile.mkstemp(".tmp", prefix=prefix, dir=".")
    507     os.close(fd)

C:\Users\bander\Anaconda3\lib\site-packages\wget.py in detect_filename(url, out, headers, default)
    482         names["out"] = out or ''
    483     if url:
--> 484         names["url"] = filename_from_url(url) or ''
    485     if headers:
    486         names["headers"] = filename_from_headers(headers) or ''

C:\Users\bander\Anaconda3\lib\site-packages\wget.py in filename_from_url(url)
    228     """:return: detected filename as unicode or None"""
    229     # [ ] test urlparse behavior with unicode url
--> 230     fname = os.path.basename(urlparse.urlparse(url).path)
    231     if len(fname.strip(" \n\t.")) == 0:
    232         return None

C:\Users\bander\Anaconda3\lib\urllib\parse.py in urlparse(url, scheme, allow_fragments)
    292     Note that we don't break the components up in smaller bits
    293     (e.g. netloc is a single string) and we don't expand % escapes."""
--> 294     url, scheme, _coerce_result = _coerce_args(url, scheme)
    295     splitresult = urlsplit(url, scheme, allow_fragments)
    296     scheme, netloc, url, query, fragment = splitresult

C:\Users\bander\Anaconda3\lib\urllib\parse.py in _coerce_args(*args)
    112     if str_input:
    113         return args + (_noop,)
--> 114     return _decode_args(args) + (_encode_result,)
    115 
    116 # Result objects are more helpful than simple tuples

C:\Users\bander\Anaconda3\lib\urllib\parse.py in _decode_args(args, encoding, errors)
     96 def _decode_args(args, encoding=_implicit_encoding,
     97                        errors=_implicit_errors):
---> 98     return tuple(x.decode(encoding, errors) if x else '' for x in args)
     99 
    100 def _coerce_args(*args):

C:\Users\bander\Anaconda3\lib\urllib\parse.py in <genexpr>(.0)
     96 def _decode_args(args, encoding=_implicit_encoding,
     97                        errors=_implicit_errors):
---> 98     return tuple(x.decode(encoding, errors) if x else '' for x in args)
     99 
    100 def _coerce_args(*args):

AttributeError: 'Request' object has no attribute 'decode'

I would be grateful if someone could help me fix this. Thanks beforehand.

Answer 1

Wget gives a HTTP Error 503: Service Temporarily Unavailable when called directly with the correct URL. I guess it is blocked at the server. The download link is generated by JavaScript. You can use Selenium. This will execute the JavaScript to get the URL. I tried Selenium with PhantomJS and it did not work. However with Chrome it did.

First install Selenium:

sudo pip3 install selenium

Then get a driver https://sites.google.com/a/chromium.org/chromedriver/downloads and put it in you path. You can use a headless version of chrome "Chrome Canary" if (unlike me) you are on Windows or Mac.

from selenium import webdriver
from time import sleep

url = 'http://sweet-home-3d.informer.com/download'
browser = webdriver.Chrome()
browser.get(url)
browser.find_element_by_class_name("download_btn").click()
sleep(360) # give it plenty of time to download this will depend on you internet connection
browser.quit()

The file will be downloaded to you Downloads folder. If it exits too soon you will get part of the file with the extra file extension .crdownload. If this happens increase the value you passed to sleep.

Answer 2

Actually you don't need Selenium for this. It's a cookie issue. I'm sure you can do cookies somehow with urllib too, but that's not my area of expertise.

If you were to do the job - without a browser and wget - in requests, you could grab the files like so:

import requests
from bs4 import BeautifulSoup as bs

# you need headers or the site won't let you grab the data
headers = {

  "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3181.0 Safari/537.36"
}
url = 'http://sweet-home-3d.informer.com/download/'

# you need a cookie to download. Create a persistens session
s = requests.Session()
r = s.get(url, headers=headers)
soup = bs(r.text, "html.parser")

# all download options lie in a div with class table
links_table = soup.find('div', {'class': 'table'})
file_name = links_table.find('div', {'class': 'table-cell file_name'})['title']
download_link = links_table.find('a', {'class': 'download_button'})['href']

# for some reason the url-page doesn't set the cookie you need.
# the subpages do, so we need to get it from one of them - before we call download_link

cookie_link = links_table.a['href']
r = s.get(cookie_link, headers=headers)

# now with a cookie set, we can download the file
r = s.get(download_link,headers=headers)
with open(file_name, 'wb') as f:
    f.write(r.content)