from array import array
a1 = array("b", [0, 1, 2, 3])
assert a1.tobytes() == b"\x00\x01\x02\x03"
assert a1[2] == 2
assert list(a1) == [0, 1, 2, 3]
a1.reverse()
assert a1 == array("B", [3, 2, 1, 0])
a1.extend([4, 5, 6, 7])
assert a1 == array("h", [3, 2, 1, 0, 4, 5, 6, 7])