Find dictionary items whose key matches a substring
<p>I have a large dictionary constructed like so:</p>

<pre><code>programs['New York'] = 'some values...' 
programs['Port Authority of New York'] = 'some values...' 
programs['New York City'] = 'some values...'
...
</code></pre>

<p>How can I return all <code>programs</code> whose key mentions "new york" (case insensitive) - which in the example above, would return all three items.</p>

<p><strong>EDIT:</strong> The dictionary is quite large and expected to get larger over time.</p>
