title: Dealing with Multiple Python Versions--- do not run independently
body: <p>I have Python 2.7 (my preferred version) and 3.3 (version used in my Programming class) installed on my computer (OS: Windows 7). Until a certain point, they worked fine independently.</p>
  
  <p>One day, one of my programs (in 3.3), got an error and crashed (it was in the command prompt, not in IDLE). After that, all of my 3.3 programs, when I attempt to edit them (edit with IDLE) or run them (in the command prompt) they open/run as 2.7 programs. This is an issue because of some of the syntax and other differences between 2.7 and 3.3.</p>
  
  <p>How can I tell my 3.3 programs to explicitly use Python 3.3? </p>
  
  <p>Right now, what I have to do is open IDLE (as a blank file, not a specific program), then use the <code>Open</code> option in IDLE. In addition, running the program with the command processor is out of the question.</p>
  
  <p>I looked it up and saw something about using <code>#!/usr/bin/env</code> but I am unsure on how to use this. Python 3.3 is installed in the following folder: <code>C:\Python3.3</code> (that's the file path).</p>
  
  <p>Thanks!</p>