What does "*" operator do before the tensor size in PyTorch?
I am now learning building neural networks in PyTorch. Here are the codes cut from the .py file:

x = torch.unsqueeze(torch.linspace(-1, 1, 1000), dim=1)
y = x.pow(2) + 0.1*torch.normal(torch.zeros(*x.size()))


I am quite comfused about the utility of the * operator before  x.size(). I tried to delete it and plot the scatter graph, which was proved the same as the one with * not removed.

I also checked the official documentation of size in https://pytorch.org/docs/stable/tensors.html but I couldn't figure it out.

Image of torch.size item in documentation

I'd appreciate it very much if you may help me.

the reason that * makes no difference in the results here is because torch.zero except both a variable number of arguments and a collection like a list or tuple as mentioned here. It does not mean * itself is useless.

Then, since torch.Size() class is a subclass of python tuple, one can unpack it using *. (x.size() will return a torch.Size() object)

So to wrap up, x.size() would give you (1000, 1) and *x.size() in the argument would give you 1000, 1 and both are accepted by torch.zeros()
