torch.isreal
torch.isreal(input) -> Tensor
Returns a new tensor with boolean elements representing if each
   element of "input" is real-valued or not. All real-valued types are
   considered real. Complex values are considered real when their
   imaginary part is 0.
Parameters:
      input (Tensor) -- the input tensor.
Returns:
      A boolean tensor that is True where "input" is real and False
      elsewhere
Example:
  >>> torch.isreal(torch.tensor([1, 1+1j, 2+0j]))
  tensor([True, False, True])
