Method visit_STANDALONE_COMMENT

src/black/linegen.py:390–431

(self, leaf: Leaf)

        yield from self.line()

    def visit_STANDALONE_COMMENT(self, leaf: Leaf) -> Iterator[Line]:
        any_open_brackets = self.current_line.bracket_tracker.any_open_brackets()
        if not any_open_brackets:
            yield from self.line()
        # STANDALONE_COMMENT nodes created by our special handling in
        # normalize_fmt_off for comment-only blocks have fmt:off as the first
        # line and fmt:on as the last line (each directive on its own line,
        # not embedded in other text). These should be appended directly
        # without calling visit_default, which would process their prefix and
        # lose indentation. Normal STANDALONE_COMMENT nodes go through
        # visit_default.
        value = leaf.value
        lines = value.splitlines()
        is_fmt_off_block = (
            len(lines) >= 2
            and contains_fmt_directive(lines[0], FMT_OFF)
            and contains_fmt_directive(lines[-1], FMT_ON)
        )
        if is_fmt_off_block:
            # This is a fmt:off/on block from normalize_fmt_off - we still need
            # to process any prefix comments (like markdown comments) but append
            # the fmt block itself directly to preserve its formatting

            # Only process prefix comments if there actually is a prefix with comments
            if leaf.prefix and any(
                line.strip().startswith("#")
                and not contains_fmt_directive(line.strip())
                for line in leaf.prefix.split("\n")
            ):
                for comment in generate_comments(leaf, mode=self.mode):
                    yield from self.line()
                    self.current_line.append(comment)
                    yield from self.line()
                # Clear the prefix since we've processed it as comments above
                leaf.prefix = ""

            self.current_line.append(leaf)
            if not any_open_brackets:
                yield from self.line()
        else:
            # Normal standalone comment - process through visit_default
            yield from self.visit_default(leaf)

    def visit_factor(self, node: Node) -> Iterator[Line]:
        """Force parentheses between a unary op and a binary power: