title: Checking actual version of Python running my code
body: <p>I would like to know the version of Python that I am using to run some code in my Linux environment.  Over time I have several versions installed and so I just want to check the version that runs my simple code when I run code from the terminal like:</p>
  <pre><code>$ ./&lt;filename&gt;.py
  </code></pre>
  <p>When I try the following, I get different conflicting answers</p>
  <pre><code>[user@localhost bin]$ /usr/bin/python -V
  Python 2.7.15
  [user@localhost bin]$ /usr/bin/python3 -V
  Python 3.6.6
  [user@localhost bin]$ python -V
  Python 2.7.15
  </code></pre>
  <p>How can I find out which version is active?</p>