Build dictionary from list comprehension over nested lists

Question

For an input nested list

[[[1, 2], [3, 4]], [[5,6]], [[7,8], [9,10], [10,10]]]

I want to build a comprehension that will assemble a nested dictionary D such that:

D[0] [1] = 2, D[0][3] = 4
D[1] [5] = 6
D[2] [7] = 8, D[2][9] = 10, D[2][10] = 10

My dictionary comprehension is the following:

dict = {k1:{v[0]:v[1]} for k1, sub in enumerate(tg1) for v in sub}

but there is a problem in that it does not contain every pair.

How do I do this?

Answer 1

If you want to use dictionary comprehension, you have to nest it. In your approach only one key-value pair gets to your inner dictionary, wherein you actually want that part to be a comprehension itself. Something like this would work:

d = {i:{k:v for k,v in sublist} for i, sublist in enumerate(l)}

Assuming l is your list here.

Answer 2

If you only have these levels of nesting, you can do it with a comprehension. On the other hand if you have more levels, you'll probably need a (recursive) function:

D = { i:dict(L) for i,L in enumerate(yourList)}

{0: {1: 2, 3: 4}, 
 1: {5: 6}, 
 2: {7: 8, 9: 10, 10: 10}}

D[0][3] # 4
D[1][5] # 6