title: Is it possible to set a proxy chain with Python's requests library?
body: <p>Here's the standard situation: a company's security policy obliges all its employees to use a company's proxy server (with authorization required) to get any https resource.</p>
  
  <p>In order to successfully use any internet connection through the Python's interpreter I have to manually:</p>
  
  <pre><code>set HTTP_PROXY=http://&lt;login&gt;:&lt;pass&gt;@&lt;proxy&gt;:&lt;port&gt;
  </code></pre>
  
  <p>If I don't do that, I'll get the following error:
  <a href="https://i.stack.imgur.com/wuyJq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wuyJq.png" alt="enter image description here"></a></p>
  
  <p>So here's the question: is it possible to connect to another proxy server (after I connected to the company's proxy somehow) in order to do some test stress work and not to endanger my company's IP to get banned?</p>