Perlin noise contours

I want to make this image by grasshopper Python.
But it’s hard to understand because it’s in JavaScript language.
Follow this link and you’ll see the images and JavaScript.

Is there anyone who can interpret this language by Python or processing?
Or what is the way to do this Perlin noise contour with Python?
I’m sorry this question is too comprehensive. But if anyone knows how, I’d really appreciate it if you could help me understand this.

Does any of the discussion help: Python implementation of Perlin Noise: how to evaluate t?

hi scottd!
Thank you for your answer.
But I think the way I want to know about the use of Perlin Noise is a little different.
I first want the particles to be expressed as one closed line as they move in the Perlin field.
So, especially in the case of JavaScript, I want to understand what special formula he used.
But it’s hard to understand because it’s different from the language I use.
I tried using Python and Perlin noise values to try the following.
What modifications would it take to do it like the JavaScript example?
perlin noise (6.0 KB) (11.4 KB)
What’s the way to make such a perfect contour?

They use iso contour, so you evaluate the noise on a grid then make iso contour. They are many ways to do this