code: def load(self, filename, using=None, parser=None, **kwargs):
          
          using = using or self.using
          parser = parser or self.parser
          if parser is None:
              raise AttributeError("A parser instance must be specified")
          # parse iterator with the specified parser
          data = parser.load(filename, **kwargs)
          # slice column by using
          return slice_columns(data, using)
docs: Load data from file using a specified parser.
  
          Return value will be separated or sliced into a column list
  
          Parameters
          ----------
          filename : string
              A data file path
          using : list of integer, slice instance, or None, optional
              A list of index or slice instance used to slice data into column
              If it is not specified, :attr:`using` specified in constructor
              will be used instead.
          parser : instance or None, optional
              An instance or registered name of parser class.
              If it is not specified, :attr:`parser` specified in constructor
              will be used instead.
  
          Returns
          -------
          ndarray
              A list of numpy array