code: def calculate_row_format(columns, keys=None):
      
      row_format = ''
      if keys is None:
          keys = columns.keys()
      else:
          keys = [key for key in keys if key in columns]
  
      for key in keys:
          if len(row_format) > 0:
              row_format += "|"
          row_format += "%%(%s)-%ds" % (key, columns[key])
  
      return '|' + row_format + '|'
docs: Calculate row format.
  
      Args:
          columns (dict): the keys are the column name and the value the max length.
          keys (list): optional list of keys to order columns as well as to filter for them.
  
      Returns:
          str: format for table row