Class Attribute

libcst/_nodes/expression.py:1622–1674

An attribute reference, such as ``x.y``. Note that in the case of ``x.y.z``, the outer attribute will have an attr of ``z`` and the value will be another :class:`Attribute` referencing the ``y`` attribute on ``x``:: Attribute( value=Attribute( v

@add_slots
@dataclass(frozen=True)
class Attribute(BaseAssignTargetExpression, BaseDelTargetExpression):
    """
    An attribute reference, such as ``x.y``.

    Note that in the case of ``x.y.z``, the outer attribute will have an attr of ``z``
    and the value will be another :class:`Attribute` referencing the ``y`` attribute on
    ``x``::

        Attribute(
            value=Attribute(
                value=Name("x")
                attr=Name("y")
            ),
            attr=Name("z"),
        )
    """

    #: An expression which, when evaluated, will produce an object with ``attr`` as an
    #: attribute.
    value: BaseExpression

    #: The name of the attribute being accessed on the ``value`` object.
    attr: Name

    #: A separating dot. If there's whitespace between the ``value`` and ``attr``, this
    #: dot owns it.
    dot: Dot = Dot()

    lpar: Sequence[LeftParen] = ()
    #: Sequence of parenthesis for precedence dictation.
    rpar: Sequence[RightParen] = ()

    def _visit_and_replace_children(self, visitor: CSTVisitorT) -> "Attribute":
        return Attribute(
            lpar=visit_sequence(self, "lpar", self.lpar, visitor),
            value=visit_required(self, "value", self.value, visitor),
            dot=visit_required(self, "dot", self.dot, visitor),
            attr=visit_required(self, "attr", self.attr, visitor),
            rpar=visit_sequence(self, "rpar", self.rpar, visitor),
        )

    def _safe_to_use_with_word_operator(self, position: ExpressionPosition) -> bool:
        if super(Attribute, self)._safe_to_use_with_word_operator(position):
            return True
        return self._check_left_right_word_concatenation_safety(
            position, self.value, self.attr
        )

    def _codegen_impl(self, state: CodegenState) -> None:
        with self._parenthesize(state):
            self.value._codegen(state)
            self.dot._codegen(state)
            self.attr._codegen(state)


class BaseSlice(CSTNode, ABC):