No module named 'torch.legacy'

[AlexRMU]

This was removed in 1.0, as it's been more than 1.5 years since PyTorch released. They also removed torch.legacy.nn in the process.
If you want to just load the weights / tensors from a .t7 file, you can try using https://github.com/bshillingford/python-torchfile or load them via pytorch 0.4.1 and save them as pickle format.