title: How to read set environment variable in python
body: <p>In UNIX from command line, I do</p>
  
  <pre><code>setenv HOME &lt;path to home&gt;
  </code></pre>
  
  <p>I pass it as argument to my python script</p>
  
  <pre><code> python hello.py HOME
  </code></pre>
  
  <p>and do </p>
  
  <pre><code>sys.argv[1] = os.environ["HOME"] 
  </code></pre>
  
  <p>still it doesn't read the path. </p>
  
  <p>I am new to python, is <code>os.environ</code> correct for this case? </p>