flatten a list of variable length arrays
<p>how to convert this:</p>

<pre><code>[2, 4, array([ 3.]), array([ 4.]), array([ 5.,  4.])]
</code></pre>

<p>to</p>

<pre><code>[2,4,3,4,5,4]
</code></pre>

<p>I've tried searching but the solutions work for</p>

<pre><code>[array([ 2.]), array([ 4.]), array([ 3.]), array([ 4.]), array([ 5.,  4.])]
</code></pre>

<p>and</p>

<pre><code>[[2],[4],[3],[4],[5,4]]
</code></pre>
