在正值和负值之间变化时拆分的列表的列表

Question

Every time the item in a list changes from a positive to negative value, start a new sub-list. For the data:

khanh = [-2.22,1.4,2,3,4,5,6,0,-2,-3,-4,-5,7,8,9]

I'm trying to output:

[[-2.22],[1.4,2,3,4,5,6,0],[-2,-3,-4,-5],[7,8,9]]

My code so far:

adam = [[prev, next] for prev, next in zip(khanh, khanh[1:]+[None])]

amber = [[currentIdx,
          khanh[idx + 1] if idx < len(khanh) - 1 else None] for idx, currentIdx in enumerate(khanh)]

robby = [x for x in khanh if x > 0 ]

print(amber)
print()
print(adam)

Answer 1

>>> lst = [-2.22,1.4,2,3,4,5,6,0,-2,-3,-4,-5,7,8,9]
>>> correct = [[-2.22],[1.4,2,3,4,5,6,0],[-2,-3,-4,-5],[7,8,9]]
>>> from itertools import groupby
>>> result = [list(g) for _, g in groupby(lst, key=lambda a: a < 0)]
>>> correct == result
True