title: How to store environment variables
body: <p>To set an environment variable using Windows Command Processor ( <code>cmd</code>) :</p>
  
  <pre><code>SET MY_VARIABLE=c:\path\to\filename.txt
  </code></pre>
  
  <p><code>MY_VARIABLE</code> now can be accessed by Python application started by same <code>cmd</code> window:</p>
  
  <pre><code>import os
  variable = os.getenv('MY_VARIABLE') 
  </code></pre>
  
  <p>I wonder if there is a way to set an environment variable from inside of Python so it becomes available to other processes running on the same machine?
  To set a new environment variable:</p>
  
  <pre><code>os.environ['NEW_VARIABLE'] = 'NEW VALUE'
  </code></pre>
  
  <p>But this <code>NEW_VARIABLE</code> is lost as soon Python process and exited.</p>