code: def drawPoints(points, bg=','):
      
  
      # Note: I set bg to ',' instead of '.' because using ... in the docstrings
      # confuses doctest and makes it think it's Python's secondary ... prompt,
      # causing doctest errors.
      import sys
      points = list(points)
      try:
          points = [(int(x), int(y)) for x, y in points]
      except:
          raise PyBresenhamException('points must only contains (x, y) numeric tuples')
  
      # Calculate size of the character grid from the given points.
      minx = min([x for x, y in points])
      maxx = max([x for x, y in points])
      miny = min([y for x, y in points])
      maxy = max([y for x, y in points])
  
      charGrid = [[' '] * (maxy - miny + 1) for i in range(maxx - minx + 1)]
  
      # Draw O characters to the grid at the given points.
      for x, y in points:
          charGrid[x - minx][y - miny] = 'O'
  
      # Print out the character grid.
      for y in range(len(charGrid[0])):
          for x in range(len(charGrid)):
              if charGrid[x][y] in (None, ' '):
                  charToDraw = bg
              else:
                  charToDraw = charGrid[x][y]
              sys.stdout.write(charToDraw)
          print()
docs: A small debug function that takes an iterable of (x, y) integer tuples
      and draws them to the screen.