How exactly does the Python function random.randint work in the background?

I don't know if stackoverflow is the right platform for such a question. But, how does the function numpy.random.randint under the hood work? For example, if I output numbers between 0 and 9. Which algorithms are behind it and can you compare it to human guessing? If you want a blind person to guess on which of 10 pictures I am currently showing?

How is the “discrete uniform” distribution achieved?