Exit python program when argument is less than 0
<p>I'd like the program to exit if the input number is less than 0, but sys.exit() isn't doing the trick. This is what I have now:</p>

<pre><code>if len( sys.argv ) &gt; 1:
    number = sys.argv[1]

if number &lt;= 0:
    print "Invalid number! Must be greater than 0"
    sys.exit()
</code></pre>
