编码火车视频中的水波纹效果Python和Pygame

I am currently trying to replicate in python/pygame (from java, p5 from the coding train video: https://www.youtube.com/watch?v=BZUdGqeOD0w) the water ripple effect. 我无法使其正常工作，屏幕保持空白（黑色：背景色），或者出现错误： Traceback (most recent call last): File "/Users/vicki/...