Python: How can I take a list of lists, convert every element into strings, and return the list of lists?
<p>For example:</p>

<pre><code>list = [[11,2,3,5],[5,3,74,1,90]]
</code></pre>

<p>returns the same thing, only everything is a str instead of an int.
I want to be able to use .join on them. Thanks!</p>
