code: def _longest_val_in_column(self, col):
          
          try:
              # +2 is for implicit separator
              return max([len(x[col]) for x in self.table if x[col]]) + 2
          except KeyError:
              logger.error("there is no column %r", col)
              raise
docs: get size of longest value in specific column
  
          :param col: str, column name
          :return int