title: Are quoted dictionary keys an absolute must?
body: <p>Just curious, made an interesting observation that I got away with defining my dictionary keys without having to quote them. I guess this is a vulnerability in Python? </p>
  
  <p>Within a sample, and not in REPL, the following does not raise an exception:</p>
  
  <pre><code>&gt;&gt;&gt; {foo:'foo', bar:'bar'}
  Traceback (most recent call last):
     File "&lt;stdin&gt;", line 1, in &lt;module&gt;
   NameError: name 'foo' is not defined
  </code></pre>
  
  <p>How do Pythonistas handle their keys? Do you advocate unquoted or quoted keys, and why?</p>