code: def uniquelines(q):
      
      setoflines = set()
      for facets in q:
          for line in itertools.combinations(facets, 2):
              setoflines.add(tuple(sorted(line)))
      return setoflines
docs: Given all the facets, convert it into a set of unique lines.  Specifically
      used for converting convex hull facets into line pairs of coordinates.
  
      Args:
          q: A 2-dim sequence, where each row represents a facet. E.g.,
              [[1,2,3],[3,6,7],...]
  
      Returns:
          setoflines:
              A set of tuple of lines.  E.g., ((1,2), (1,3), (2,3), ....)