check this out but summary use torch.stack if you want to respect the original nesting of the lists (by having a tensor with many indices and dimensions) and incrementally create it. There might be better ways but that works for me.

  
    
    
    Best way to convert a list to a tensor? 
  
  
    hahaha, yea I see I didn’t make a very solid memory/understanding when I wrote that last year (or it’s been to long since?). Perhaps I can finally sort this out in my head, though in my defence, there does seem to be a lot of discussions surrounding this topic (which isn’t helping to digest this): 

How to convert array to tensor? - #25 by mehran2020
How to turn a list of tensor to tensor? - #9 by Nithin_Vasisth
How to turn a list of tensor to tensor? - #10 by Brando_Miranda
Converting list to t…
  



# %%

import torch

# stack vs cat

# cat "extends" a list in the given dimension e.g. adds more rows or columns

x = torch.randn(2, 3)
print(f'{x.size()}')

# add more rows (thus increasing the dimensionality of the column space to 2 -> 6)
xnew_from_cat = torch.cat((x, x, x), 0)
print(f'{xnew_from_cat.size()}')

# add more columns (thus increasing the dimensionality of the row space to 3 -> 9)
xnew_from_cat = torch.cat((x, x, x), 1)
print(f'{xnew_from_cat.size()}')

print()

# stack serves the same role as append in lists. i.e. it doesn't change the original
# vector space but instead adds a new index to the new tensor, so you retain the ability
# get the original tensor you added to the list by indexing in the new dimension
xnew_from_stack = torch.stack((x, x, x, x), 0)
print(f'{xnew_from_stack.size()}')

xnew_from_stack = torch.stack((x, x, x, x), 1)
print(f'{xnew_from_stack.size()}')

xnew_from_stack = torch.stack((x, x, x, x), 2)
print(f'{xnew_from_stack.size()}')

# default appends at the from
xnew_from_stack = torch.stack((x, x, x, x))
print(f'{xnew_from_stack.size()}')

print('I like to think of xnew_from_stack as a \"tensor list\" that you can pop from the front')

print()

lst = []
print(f'{x.size()}')
for i in range(10):
    x += i  # say we do something with x at iteration i
    lst.append(x)
# lstt = torch.stack([x for _ in range(10)])
lstt = torch.stack(lst)
print(lstt.size())

print()

# lst = []
# print(f'{x.size()}')
# for i in range(10):
#     x += i  # say we do something with x at iteration i
#     for j in range(11):
#         x += j
#         lstx
#     lst.append(x)
# # lstt = torch.stack([x for _ in range(10)])
# lstt = torch.stack(lst)
# print(lstt.size())