struct

import struct

data = struct.pack("<BhI", 0xAA, -100, 0x12345678)
print(data)

a, b, c = struct.unpack("<BhI", data)
print(hex(a), b, hex(c))

raw = b"\x01\x02\x03\x04"
nums = list(struct.unpack("<" + "B" * len(raw), raw))
print(nums)