Method _f_col

tables/table.py:3318–3346

Get an accessor to the column colname. This method returns a Column instance (see :ref:`ColumnClassDescr`) if the requested column is not nested, and a Cols instance (see :ref:`ColsClassDescr`) if it is. You may use full column pathnames in colname. Calling

(self, colname: str)

        return len(self._v_colnames)

    def _f_col(self, colname: str) -> Cols:
        """Get an accessor to the column colname.

        This method returns a Column instance (see :ref:`ColumnClassDescr`) if
        the requested column is not nested, and a Cols instance (see
        :ref:`ColsClassDescr`) if it is.  You may use full column pathnames in
        colname.

        Calling cols._f_col('col1/col2') is equivalent to using cols.col1.col2.
        However, the first syntax is more intended for programmatic use.  It is
        also better if you want to access columns with names that are not valid
        Python identifiers.

        """
        if not isinstance(colname, str):
            raise TypeError(
                f"Parameter can only be an string. You passed object: "
                f"{colname}"
            )
        if (
            colname.find("/") > -1 and colname not in self._v_colpathnames
        ) and colname not in self._v_colnames:
            raise KeyError(
                f"Cols accessor "
                f"``{self._v__tablePath}.cols{self._v_desc._v_pathname}`` "
                f"does not have a column named ``{colname}``"
            )

        return self._g_col(colname)

    def _g_col(self, colname: str) -> Cols:
        """Like `self._f_col()` but it does not check arguments."""