Compute the vectorized membership of ``x in y`` if possible, otherwise
    use Python.

def _in(x, y):
    """Compute the vectorized membership of ``x in y`` if possible, otherwise
    use Python.
    """
    try:
        return x.isin(y)
    except AttributeError:
        if is_list_like(x):
            try:
                return y.isin(x)
            except AttributeError:
                pass
        return x in y