No there isn’t a pretty built-in way.
There are however a lot of ugly ways of doing so. You can, for instance, define torch.pi at run-time:
import torch
torch.pi = torch.acos(torch.zeros(1)).item() * 2 # which is 3.1415927410125732

You can even modify the __init__.py file (which is located in print(torch.__file__)) in your environment by adding a line with pi = 3.14 etc, so that you will always be able to use the torch.pi constant.