Check for the existence of a string in a list of tuples
<p>If i have:</p>

<pre><code>my_list = (('foo', 'bar'), ('floo', 'blar'))
</code></pre>

<p>how can i easily test if some string is in the first element in any of those tuples?</p>

<p>something like:</p>

<pre><code>if 'foo' in my_list
</code></pre>

<p>where we are just checking the first element of each tuple in the list?</p>
