Click “Evaluate” after each of the pieces of code to see a 3d plot of the surface. You can edit the code to get it to plot any parametrized surface you wish to see.
There is more about SageMath at the bottom of the page.
SageMath is a computer algebra system like Mathematica and Maple but it is free, open source and is written in Python.
If you have any questions about SageMath then feel free to come talk to me.