new.py

def _find_neg_rect(image, pos_rects):
    image_width, image_height = image.shape
    rand = partial(random.randint, 1)
    while True:
        x = rand(image_width - 1)
        width = rand(image_width - x)
        y = rand(image_height - 1)
        height = rand(image_height - y)

        random_rect = Rect(x, y, width, height)
        if any(map(lambda x: is_same_target(random_rect, x, 0), pos_rect)):
            return random_rect