title: converting a string to a list of tuples
body: <p>I need to convert a string, <code>'(2,3,4),(1,6,7)'</code> into a list of tuples <code>[(2,3,4),(1,6,7)]</code> in Python.
  I was thinking to split up at every <code>','</code> and then use a for loop and append each tuple to an empty list. But I am not quite sure how to do it.
  A hint, anyone?</p>