Question

Example:
From this list:

list = [[10, 9, 1], [2, 1, 1,], [4, 11, 16]]

I’d like to have:

print list
[[1, 1, 1], [2, 4, 9], [10, 11, 16]]

Is it possible with the list.sort() function or do I have to write a custom loop ?

Answer 1

Here’s an example of flattening, sorting, then rebuilding the nested lists, as @Inerdia suggested in the comments above.

I’ve tried to use generators and iterators where possible, but I’m sure there are cleverer, more efficient ways of getting the result!

from itertools import izip

l = [[10, 9, 1], [2, 1, 1,], [4, 11, 16]]
# flatten the list and sort it
f = sorted(inner for outer in l for inner in outer)
# group it into 3s again using izip
new_list = [list(l) for l in izip(*[iter(f)]*3)]