def set_cols_dtype(self, array):
        """Set the desired columns datatype for the cols.

        - the elements of the array should be either a callable or any of
          "a", "t", "f", "e" or "i":

            * "a": automatic (try to use the most appropriate datatype)
            * "t": treat as text
            * "f": treat as float in decimal format
            * "e": treat as float in exponential format
            * "i": treat as int
            * a callable: should return formatted string for any value given

        - by default, automatic datatyping is used for each column
        """

        self._check_row_size(array)
        self._dtype = array
        return self
Set the desired columns datatype for the cols.

        - the elements of the array should be either a callable or any of
          "a", "t", "f", "e" or "i":

            * "a": automatic (try to use the most appropriate datatype)
            * "t": treat as text
            * "f": treat as float in decimal format
            * "e": treat as float in exponential format
            * "i": treat as int
            * a callable: should return formatted string for any value given

        - by default, automatic datatyping is used for each column