[FIXED] How to convert a list in list to torch tensor?

Issue

I want to convert a list of list to torch.LongTensor.

The element in a list of sequence means embedding index, and each list has different size.

For example,

tmp = [[7, 1], [8, 4, 0], [9]]
tmp = torch.LongTensor(tmp)

This occrus TypeError: not a sequence

How can I convert different sizes of a list in list to torch Tensor?

Solution

This will solve your issue:

tmp = torch.LongTensor(list(map(lambda x: x + [0] * (max(map(len, tmp)) - len(x)), tmp)))

Explanation:

# 1
map(lambda x: x + [0] * (max(map(len, tmp)) - len(x)), tmp)
  # -> [[7, 1, 0], [8, 4, 0], [9, 0, 0]]

# 2
torch.LongTensor([[7, 1, 0], [8, 4, 0], [9, 0, 0]])
  # -> tensor([[7, 1, 0],
  #            [8, 4, 0],
  #            [9, 0, 0]])

Answered By - Jiya