title: Python Requests response is different from chrome response
body: <p>I need to download about 100 captcha images from a particular website.
  My code in summary is:</p>
  
  <p>1- download the page</p>
  
  <p>2- search for the captcha image URL (using re) and download it</p>
  
  <p>3- :( the downloaded image is different from what I'd see in browser. I guess there is a parameter in session or in the request (get or post) I need to set, which I haven't.</p>
  
  <pre><code>import requests
  import re
  import time
  s = requests.Session()
  headers = {'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36'}
  
  #download this page and look for the url of the captcha image
  page = s.get('http://www.rrk.ir/News/ShowOldNews.aspx?Code=1', headers=headers)
  result = re.search('img id="imgCaptcha" src="..(.*)"', page.content.decode('utf-8'))
  img_url = 'http://www.rrk.ir' + result.group(1).split('"')[0]
  
  print(img_url)
  #download the image and save it to a file
  img = s.get(img_url, headers=headers)
  img_file_name =  './a'  + '.jpg'
  with open(img_file_name, 'wb') as fout:
      fout.write(img.content)
  
  s.close()
  #:( the downloaded file is different from what I see in Chrome.
  </code></pre>
  
  <p>How can I find out what setting I'm missing?</p>
  
  <p><strong>Update 1</strong>: As suggested, added the custom headers but it didn't help.</p>