How to install Pytorch for CUDA?

Question

Python

Requires installing Pytorch for CUDA.
Now when I call the commands, the output is:

$ cat /usr/local/cuda/version.txt
CUDA Version 10.0.130
$ nvcc --version | grep "release" | awk '{print $6}' | cut -c2-
9.1.85

$ python
>>> import torch
>>> torch.cuda.is_available()
False

Do I understand correctly that I have two different versions of CUDA on my computer? How can you adapt at least something so that pytorch picks up cuda?
Thanks in advance!