expression.py 文件源码

def append_column(self, column):
        """append the given column expression to the columns clause of this
        select() construct.

        This is an **in-place** mutation method; the
        :meth:`~.Select.column` method is preferred, as it provides standard
        :term:`method chaining`.

        """
        self._reset_exported()
        column = _interpret_as_column_or_from(column)

        if isinstance(column, ScalarSelect):
            column = column.self_group(against=operators.comma_op)

        self._raw_columns = self._raw_columns + [column]