how to traverse through dict?
<pre><code>records = {'foo':foo, 'bar':bar, 'baz':baz}
</code></pre>

<p>I want to change the values to <code>0</code> if it is <code>None</code>. How can I do this?</p>

<p>eg:</p>

<pre><code>records = {'foo':None, 'bar':None, 'baz':1}
</code></pre>

<p>I want to change <code>foo</code> and <code>bar</code> to <code>0</code>.
Final dict: </p>

<pre><code>records = {'foo':0, 'bar':0, 'baz':1}
</code></pre>
