The tensordot function is not consistent throughout different backends

[Canoming]

When I try to call the function tensordot from different backends, the arguments are not consistent:

  if self._backend.__class__.__name__ == "PyTorchBackend":
      tensor = self._backend.np.tensordot(tensor0, tensor1, dims=([1],[0]))
  else:
      tensor = self._backend.np.tensordot(tensor0, tensor1, axes=(1,0))

The argument axes is named dims in PyTorchBackend, which is different from all other backends. Also, the type of argument is different. While other backends support tuple of numbers for axes, the PyTorchBackend only support tuple of list.

[Simone-Bordoni]

We are planning on defining the function tensordot in the abstract backend. For now a good solution is using matmul that seems to work in the same way for all backends.

[renatomello]

@Canoming @Simone-Bordoni can this be closed?