Check if an item is in a nested list : <p>in a simple list following check is trivial:</p>

<pre><code>x = [1, 2, 3]

2 in x  -&gt; True
</code></pre>

<p>but if it is a list of list, such as:</p>

<pre><code>x = [[1, 2, 3], [2, 3, 4]]

2 in x   -&gt; False
</code></pre>

<p>how can this be addressed in order to return <code>True</code>?</p>
