Saving the dictionary with str keys and a list of pytorch tensors as values

I want to save a list of dictionary in which keys are indices of queries (so the keys of the dictionary are strings). The values of this dictionary are list of sparse tensors which I store as follows :

{'1185869': [tensor(indices=tensor([[   31,    59,   528,  7227, 14981]]),
         values=tensor([1., 1., 1., 1., 1.]),
         size=(30000,), nnz=5, layout=torch.sparse_coo),
  tensor(indices=tensor([[ 39,  74, 233]]),
         values=tensor([1., 1., 1.]),
         size=(30000,), nnz=3, layout=torch.sparse_coo),
  tensor(indices=tensor([[0, 1, 2]]),
         values=tensor([1., 1., 1.]),
         size=(30000,), nnz=3, layout=torch.sparse_coo),
  tensor(indices=tensor([[  36,   99,  243,  428,  513,  514,  741,  751, 1615]]),
         values=tensor([1., 1., 1., 1., 1., 1., 1., 1., 1.]),
         size=(30000,), nnz=9, layout=torch.sparse_coo),
  tensor(indices=tensor([[ 170,  356,  513,  615,  771, 1117]]),
         values=tensor([1., 1., 1., 1., 1., 1.]),
         size=(30000,), nnz=6, layout=torch.sparse_coo),
  tensor(indices=tensor([[ 9, 11]]),
         values=tensor([1., 1.]),
         size=(30000,), nnz=2, layout=torch.sparse_coo)]}

I've not saved any such dictionary before. Generally for normal dictionaries, we pickle it. If I pickle this dictionary, I'm getting a pytorch warning. This makes me doubt the method I'm using to save the dictionary. What extensions should I use to save such dictionary? Is pickling such dictionary safe? What method should I use to save it? Thanks in advance.