code: def clean(self, line):
          
          # print ("-" + line + "-")
          if line == '':
              line = 'None'
          if self.is_lower:
              line = line.lower()
          if line == "user ":  # for slurm which has "user" and "user "
              line = "userid"
          for convert in self.change:
              line = line.replace(convert[0], convert[1])
          if self.is_strip:
              line = line.strip()
          return line.strip(' ')
docs: :param line: cleans the string
          :return: