code: def column_converter(string):
      
      column = string.strip(',')
      if '-' in column:
          column_range = map(int, column.split('-'))
          # For decreasing ranges, increment the larger value, reverse the
          # passing to range (so it will accept the input), and finally
          # reverse the output ([::-1])
          if column_range[0] > column_range[1]:
              column_range[0] += 1
              return [i for i in range(*column_range[::-1])][::-1]
          # For normal ranges, increment the larger value.
          column_range[1] += 1
          return [i for i in range(*column_range)]
      if ',' in column:
          columns = column.split(',')
          return map(int, columns)
      return [int(column)]
docs: Converts column arguments to integers.
  
      - Accepts columns in form of INT, or the range INT-INT.
      - Returns a list of one or more integers.