title: How to pip install for certain version of python
body: <p>I need to install <code>requests</code> globally for python3</p>
  
  <pre><code>pip install requests
  </code></pre>
  
  <p>installs it for python2.7.</p>
  
  <p>How to do this without <code>virtualenv</code> ?</p>
  
  <p>I have no <code>pip3</code>.</p>
  
  <p>Same problem for <code>lxml</code> installation.</p>