Class _UnparseVisitor

sphinx/pycode/ast.py:52–209

# a greatly cut-down version of `ast._Unparser`
class _UnparseVisitor(ast.NodeVisitor):
    def __init__(self, code: str = '') -> None:
        self.code = code

    def _visit_op(self, node: ast.AST) -> str:
        return OPERATORS[node.__class__]

    for _op in OPERATORS:
        locals()[f'visit_{_op.__name__}'] = _visit_op

    def visit_arg(self, node: ast.arg) -> str:
        if node.annotation:
            return f'{node.arg}: {self.visit(node.annotation)}'
        else:
            return node.arg

    def _visit_arg_with_default(self, arg: ast.arg, default: ast.AST | None) -> str:
        """Unparse a single argument to a string."""
        name = self.visit(arg)
        if default:
            if arg.annotation:
                name += ' = %s' % self.visit(default)
            else:
                name += '=%s' % self.visit(default)
        return name

    def visit_arguments(self, node: ast.arguments) -> str:
        defaults: list[ast.expr | None] = list(node.defaults)
        positionals = len(node.args)
        posonlyargs = len(node.posonlyargs)
        positionals += posonlyargs
        for _ in range(len(defaults), positionals):
            defaults.insert(0, None)

        kw_defaults: list[ast.expr | None] = list(node.kw_defaults)
        for _ in range(len(kw_defaults), len(node.kwonlyargs)):
            kw_defaults.insert(0, None)

        args: list[str] = [
            self._visit_arg_with_default(arg, defaults[i])
            for i, arg in enumerate(node.posonlyargs)
        ]

        if node.posonlyargs:
            args.append('/')

        for i, arg in enumerate(node.args):
            args.append(self._visit_arg_with_default(arg, defaults[i + posonlyargs]))

        if node.vararg:
            args.append('*' + self.visit(node.vararg))

        if node.kwonlyargs and not node.vararg:
            args.append('*')
        for i, arg in enumerate(node.kwonlyargs):
            args.append(self._visit_arg_with_default(arg, kw_defaults[i]))

        if node.kwarg: