def colorscale_to_scale(colorscale):
 scale_list = []
 for item in colorscale:
  scale_list.append(item[0])
 return scale_list

def colorscale_to_scale ( colorscale ) : scale_list = [ ] for item in colorscale : scale_list . append ( item [ 0 ] ) return scale_list
extracts the interpolation scale values from colorscale as a list .