title: How to change default idle for python (Ubuntu)?
body: <p>Okay, so I have python 3.5 on my system (Ubuntu 16.04). Whenever I open a <code>.py</code> file, Idle3 starts, thus pressing <kbd>F5</kbd> will instantly run my code.</p>
  
  <p>However I need python 2.7 now for an assignment. In terminal I've <code>apt-get install idle</code> so, I can open idle and idle3 there easily.</p>
  
  <p>My problem is, I can't change my <code>.py</code> files' default application to idle. It only sees idle3, so I can't open my files with idle(2.7) as default.</p>
  
  <p>Tried to make an alias in ~/.bash_aliases as <code>alias python=/usr/local/bin/python2.7</code>, but typing <code>python --version</code> into terminal I get: </p>
  
  <p><code>-bash: /usr/local/bin/python2.7: No such file or directory</code>.</p>
  
  <p>Typing <code>python2 --version</code> and  <code>python3 --version</code> works fine.</p>
  
  <p>Is there any simple workaround for that?</p>