How to access key in Python dictionary
<p>I know it's possible to traverse a dictionary by using <code>iteritems()</code> or <code>keys()</code>. But what if I got a list of dics such as: <code>l = [{'a': 1}, {'b': 2}, {'c': 3}]</code> and I want to compose a string using its keys, e.g., <code>s = 'a, b, c'</code>?</p>

<p>One solution is to copy all the keys into a list in advance, and compose the string I want. Just wondering if there is a better solution.</p>
