仅更改散点图的数据怎么办?

What about just changing the data of your scatter plot?

# save an empty scatter plot
scat = plt.scatter([], [],  s=2.5, alpha=1, color=c, edgecolors='none')
for each set in sets:
    # The data needs to be written as [(x1, y1), (x2, y2), ...]
    scat.set_offsets([xy for xy in zip(x, y)])
    plt.savefig("...")