How to iterate over Python dictionary keys : <p>I have a dictionary as follows. How can I iterate over all the values in the dictionary with matching first and second keys? for example iterate over all ('picture','angie',*) in the following dictionary </p>

<pre><code>book = 
{('poem', 'jim', '1'): '$50', 
 ('poem', 'jim', '2'): '$51', 
 ('picture', 'angie', '1'): '$90', 
 ('picture', 'angie', '2'): '$10', 
 ('picture', 'angie', '3'): '$20'}
</code></pre>

<p>would return</p>

<pre><code> ('picture', 'angie', '1'): '$90'
 ('picture', 'angie', '2'): '$10' 
 ('picture', 'angie', '3'): '$20'
</code></pre>
