Adding List Element if Second part of the List Elements are the Same

[bowlofred]

Trying to do this entirely within a list seems possible, but annoying to me. You're treating the bit on the end like a dictionary key. So I'd recommend creating a real dictionary instead. Then if you need the lists later, reassemble them from the dictionary.

Actually storing the data in a dictionary seems much better than forcing everything into a four-deep nested list structure.

from collections import defaultdict
import pprint

newlist = [[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],(1.57, 1.57, 0)],
[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]], (0, 1.57, 0)],
[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]], (0, 1.57, 1.57)],
[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]], (0, 0, 0)],
[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]], (0, 1.57, 0)]]

info = defaultdict(list)

#dict from the list
for row in newlist:
    sublist, key = row
    info[key].append(sublist)

# reassmble the list
newlist = []
for key, value in info.items():
    sublist = value
    sublist.append(key)
    newlist.append(value)

pprint.pprint(newlist)

Output:
[[[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],
  (1.57, 1.57, 0)],
 [[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],
  [[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],
  (0, 1.57, 0)],
 [[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],
  (0, 1.57, 1.57)],
 [[[0, 0, 0], [1, 1, 0], [0, 1, 0], [0, 0, 0], [1, 0, 1], [1, 1, 1]],
  (0, 0, 0)]]