Write and read function(t). Previous thead not completed

I want to make a similation so I’m dealing with a 3 dimensional Space, a 3 Dimensional function
u->(x->,t)
Where → is for vector notation.

I have seen that it was an unsolved problem in other threads. 1. People didn’t know how to read from the xmdf or h5 and obtain U(X,T).

Paraview can show it, with the time step and all, but I don’t know how to read it.

The part about reading the different time step has eluded me.

So, for now, I’ve dealt with using single threading and h5py to write (I think using MPI to brute force my current setup would cause concurancy issue if I used multithreading. If there’s a way to collect the data in one thread, then do whatever I want, and then give fenicw the multithreading, that would be nice.)

But if not, I’d like an example of how to read the function and get u(x,y,z,t,dimension_index).

I found nothing in previous discussion theead on how to do it and one of them even concluded that read/write is bugged and shouldn’t be used, but its old, so that problem might have been fixed.

Thanks