Thank you.
But it does not work, the weights of the model do not change after the loading for both solutions :
model = torch.nn.Linear(4,4)
save = model
#training here
print(net.weight.data)
model = save
print(net.weight.data)
#Same result for both print

model = torch.nn.Linear(4,4)
save = model.state_dict()
#training here
print(net.weight.data)
model.load_state_dict(save)
print(net.weight.data)
#Same result for both print