Function _stringify_ast

src/black/parsing.py:188–258

(node: ast.AST, parent_stack: list[ast.AST])

def _stringify_ast(node: ast.AST, parent_stack: list[ast.AST]) -> Iterator[str]:
    if (
        isinstance(node, ast.Constant)
        and isinstance(node.value, str)
        and node.kind == "u"
    ):
        # It's a quirk of history that we strip the u prefix over here. We used to
        # rewrite the AST nodes for Python version compatibility and we never copied
        # over the kind
        node.kind = None

    yield f"{'    ' * len(parent_stack)}{node.__class__.__name__}("

    for field in sorted(node._fields):
        # TypeIgnore has only one field 'lineno' which breaks this comparison
        if isinstance(node, ast.TypeIgnore):
            break

        try:
            value: object = getattr(node, field)
        except AttributeError:
            continue

        yield f"{'    ' * (len(parent_stack) + 1)}{field}="

        if isinstance(value, list):
            for item in value:
                # Ignore nested tuples within del statements, because we may insert
                # parentheses and they change the AST.
                if (
                    field == "targets"
                    and isinstance(node, ast.Delete)
                    and isinstance(item, ast.Tuple)
                ):
                    for elt in _unwrap_tuples(item):
                        yield from _stringify_ast_with_new_parent(
                            elt, parent_stack, node
                        )

                elif isinstance(item, ast.AST):
                    yield from _stringify_ast_with_new_parent(item, parent_stack, node)

        elif isinstance(value, ast.AST):
            yield from _stringify_ast_with_new_parent(value, parent_stack, node)

        else:
            normalized: object
            if (
                isinstance(node, ast.Constant)
                and field == "value"
                and isinstance(value, str)
                and len(parent_stack) >= 2
                # Any standalone string, ideally this would
                # exactly match black.nodes.is_docstring
                and isinstance(parent_stack[-1], ast.Expr)
            ):
                # Constant strings may be indented across newlines, if they are
                # docstrings; fold spaces after newlines when comparing. Similarly,