Pytorch doesn’t have such a functionality by default.
Lua-Torch used to have such functionality (getParameters() would return a view of all the parameters concatenated into a single huge tensor), but it turned out there were many corner cases that made a proper implementation difficult.
But you can always have an approximation of it using simple elementary functions. For example, to append all the parameters in a single tensor in PyTorch, you could do something like
param_list = list(p.view(-1) for p in model.parameters())
concat_param = torch.cat(param_list)