group = []
for item in iterable:
    if not prev or item - prev <= 15:
        group.append(item)
else:
    yield group
group = [item]
prev = item
if group:
    yield group
numbers = [123, 124, 128, 160, 167, 213, 215, 230, 245, 255, 257, 400, 401,
    402, 430]
dict(enumerate(grouper(numbers), 1))
Поиск кластеров чисел в списке