title: Convert list of lists of string into floats
body: <p>I have a list of lists, that every list contains a string. I want to convert every string in the list to float numbers. Instead of having one element in the list ( a string ), I want my list to contain multiple floats</p>
  
  <pre><code> [['1,10,300,0.5,85'],
    ['3,16,271,2.9,89'],...
  </code></pre>
  
  <p>To:</p>
  
  <pre><code>[[1,10,300,0.5,85],
   [3,16,271,2.9,89],... 
  </code></pre>
  
  <p>How can i do it? 
  Thank you</p>