code: def run(itf):
      
  
      if not itf:
          return 1
  
      # access user input
      options = SplitInput(itf)
  
      # read input
      print(" Reading input file ...")
      molecules = csv_interface.read_csv(os.path.abspath(options.inputpath), options)
      if not molecules:
          print("\n '{f} was unable to be parsed\n".format(f=os.path.basename(options.inputpath)))
          sys.exit(1)
      approximator(molecules, options)
docs: run approximate functions
      :param itf:
      :return: