'append the given FromClause expression to this select() construct\'s
FROM clause.
This is an **in-place** mutation method; the
:meth:`~.Select.select_from` method is preferred, as it provides standard
:term:`method chaining`.'

def append_from(self, fromclause):

    self._reset_exported()
    fromclause = _interpret_as_from(fromclause)
    self._from_obj = self._from_obj.union([fromclause])
