routing.py

import ast
import types
from typing import Final

#: That's how python types and ast types map to each other, copied from ast.
_CONST_NODE_TYPE_NAMES: Final = types.MappingProxyType(
    {
        bool: 'NameConstant',  # should be before int
        type(None): 'NameConstant',
        int: 'Num',
        float: 'Num',
        complex: 'Num',
        str: 'Str',
        bytes: 'Bytes',
        type(...): 'Ellipsis',
    },
)


def route_visit(self: ast.NodeVisitor, node: ast.AST) -> None:
    """
    Custom router for python3.8+ release.

    Hacked to make sure that everything we had defined before is working.
    """
    if isinstance(node, ast.Constant):
        # That's the hack itself, we don't get the name of the node.
        # We get the name of wrapped type from it.
        type_name = _CONST_NODE_TYPE_NAMES.get(type(node.value))
    else:
        type_name = node.__class__.__name__

    return getattr(  # type: ignore[no-any-return]
        self,
        f'visit_{type_name}',
        self.generic_visit,
    )(node)