from typing import Iterable


def xy_flatten(iterable: Iterable[Iterable[float]]) -> Iterable[float]:
    """
        Flatten [(x, y)...] to [x, y, ...].  Inverse of xy_iter()

        Note: This will actually flatten any iterable of iterables, but the
        intent is just for graphical things like (1, 2) or Point(3, 4).
    """

    return (v for xy in iterable for v in xy)