title: Why python allows to overwrite builtin constants?
body: <p>Although <code>True</code>, <code>False</code> are <a href="http://docs.python.org/2/library/constants.html" rel="nofollow">builtin constants</a>, the following is allowed in Python.</p>
  
  <pre><code>&gt;&gt;&gt; True = False
  &gt;&gt;&gt; a = True
  &gt;&gt;&gt; b = False
  &gt;&gt;&gt; print a,b
  False False
  </code></pre>
  
  <p>Any reference of why this is allowed?</p>
  
  <p><strong>EDIT:</strong> This happens only in Python 2.x (as all pointed out).</p>