title: Request [503] in requests and User Agent isn't working
body: <p>I'm trying to access this website via Python, which first requires a log-in:
  <a href="https://nitrogensports.eu/" rel="nofollow noreferrer">https://nitrogensports.eu/</a></p>
  
  <p>This is my script so far:</p>
  
  <pre><code>from bs4 import BeautifulSoup
  import requests, urllib, html5lib
  
  url = 'https://nitrogensports.eu/'
  user_agent = {'User-Agent' : 'Mozilla/5.0'}
  response = requests.get(url, headers = user_agent)
  </code></pre>
  
  <p>This gives me: </p>
  
  <pre><code>&lt;Response [503]&gt;
  </code></pre>
  
  <p>I've logged into websites before by inspecting elements for the username and password box and what not, but I am not even able to get the first HTML tree with this website. I've tried some other things such as changeing my user_agent to:</p>
  
  <pre><code>user_agent = {'User-Agent' : 'Mozilla/5.0 (Windows NT 6.1; Win64; x64;en; rv:5.0) Gecko/20110619 Firefox/5.0'
  </code></pre>
  
  <p>but I keep getting 503</p>
  
  <p>Could someone help me retrieve even the HTML structure of the webpage without anything to do with username of password? Thanks</p>