title: python: convert 2 dimension list of string to float
body: <p>I have a 2 dimension list of type string I'm trying to convert it to int. Things I've tried so far: </p>
  
  <pre><code>[[float(i) for i in lst[j] for j in lst]
  </code></pre>
  
  <p>with a for loop:</p>
  
  <pre><code>for i in range(len(lst)):
      for j in range(len(lst[i])):
           lst[i][j]=float(lst[i][j])
  </code></pre>