Type checking for Python and JS objects

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I find myself using this little util a lot. It’s essentially a merge of Python’s ‘isinstance’ function and JS’ ‘instanceof’ operator. Perhaps you’ll find it useful too.

from anvil.js.window import Function as _Function, Object as _Object
from anvil.js import new as _new

_isInstance = _new(_Function, "value", "ref", "return value instanceof ref;")

def is_instance_of(value, ref) -> bool:
    """Special hybrid of Python's 'isinstance' function and JS' 'instanceof' operator. 
    Interprets 'int' as excluding Booleans."""
    if not isinstance(ref, tuple):
        ref = (ref,)
    for r in ref:
        if isinstance(r, type):
            if r is int:
                # Ensure that True and False are not interpreted as 'int' (which they are in Python)
                if isinstance(value, int) and not isinstance(value, bool):
                    return True
            else:
                if isinstance(value, r):
                    return True
        elif _isInstance(r, _Object):
            if _isInstance(value, r):
                return True
        else:
            raise TypeError(
                f"Invalid type, '{type(r)}' for {r}. Expected instance of 'type' or JS object."
            )
    return False
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