title: How do you find the length of a list inside a list? (Python3)
body: <p>At the moment, I'm just testing this out and will add it to my program once I understand it. I'd just like to know how to find the length of a list inside a list.</p>
  
  <p>I've tried:</p>
  
  <pre><code>l = [["1","2","3"],["1","2","3","4"],["1","2","3","4","5"]]
  [print(len(x)) for x in l[0]]
  </code></pre>
  
  <p>But it just prints 1 three times. I just need it to print (or return) the lengths of each list inside <code>l</code>.</p>