Function wrap_in_parentheses

src/black/nodes.py:990–1005

Wrap `child` in parentheses. This replaces `child` with an atom holding the parentheses and the old child. That requires moving the prefix. If `visible` is False, the leaves will be valueless (and thus invisible).

(parent: Node, child: LN, *, visible: bool = True)

def wrap_in_parentheses(parent: Node, child: LN, *, visible: bool = True) -> None:
    """Wrap `child` in parentheses.

    This replaces `child` with an atom holding the parentheses and the old
    child.  That requires moving the prefix.

    If `visible` is False, the leaves will be valueless (and thus invisible).
    """
    lpar = Leaf(token.LPAR, "(" if visible else "")
    rpar = Leaf(token.RPAR, ")" if visible else "")
    prefix = child.prefix
    child.prefix = ""
    index = child.remove() or 0
    new_child = Node(syms.atom, [lpar, child, rpar])
    new_child.prefix = prefix
    parent.insert_child(index, new_child)


def unwrap_singleton_parenthesis(node: LN) -> LN | None: