Another example: the unimport project ("linter, formatter for finding and removing unused import statements") uses the following function to guess if a module object is part of the stdlib:

def is_std(package: str) -> bool:
    """Returns True if package module came with from Python."""

    if package in C.BUILTIN_MODULE_NAMES:
        return True
    spec = get_spec(package)
    if spec and isinstance(spec.origin, str):
        return any(
            (
                spec.origin.startswith(C.STDLIB_PATH),
                spec.origin in ["built-in", "frozen"],
                spec.origin.endswith(".so"),
            )
        )
    else:
        return False

https://github.com/hakancelik96/unimport/blob/c9bd5de99bd8a5239d3dee2c3ff633979bb3ead2/unimport/utils.py#L61-L77