title: TypeError: list indices must be integers, not tuple, whats wrong
body: <p>New in Python, help.
  Why i get this error:
  "TypeError: list indices must be integers, not tuple,"</p>
  
  <pre><code>imheight = []
  for i in range(0,len(tables)):
      for j in range(0,len(tables)):
        hij = computeHeight(imp[i],imp[j],'Meter')
        imheight[i,j] = hij
        imheight[j,i] = hij
  </code></pre>