>>> data = [123,452,342,533,222,402,124,125,263,254,44,987,78,655,741,165,597,26,15,799,100,154,122,563] 
>>> sizes = [2, 5, 14, 3]
>>> it = iter(data)
>>> [[next(it) for _ in range(size)] for size in sizes]
[[123, 452],
 [342, 533, 222, 402, 124],
 [125, 263, 254, 44, 987, 78, 655, 741, 165, 597, 26, 15, 799, 100],
 [154, 122, 563]]