BMDan

from typing import Any, Dict, List, Mapping, Union

# Values for JSON that aren't nested
JSON_v = Union[str, int, float, bool, None]

# If MyPy ever permits recursive definitions, just uncomment this:
# JSON = Union[List['JSON'], Mapping[str, 'JSON'], JSON_v]

# Until then, here's a multi-layer way to represent any (reasonable) JSON we
# might send or receive.  It terminates at JSON_4, so the maximum depth of