torch.nonzero

import torch
a=torch.randint(-1,2,(10,),dtype=torch.int)
print(a)
print(a.size())
print(torch.nonzero(a))
print(torch.nonzero(a).size())



Output:
-------------------------------------------------------------------------
    tensor([ 0, -1,  1,  1, -1,  0,  1, -1, -1, -1], dtype=torch.int32)
    torch.Size([10])
    tensor([[1],
            [2],
            [3],
            [4],
            [6],
            [7],
            [8],
            [9]])
    torch.Size([8, 1])
-------------------------------------------------------------------------