# test bytearray + bytearray b = bytearray(2) b[0] = 1 b[1] = 2 print(b + bytearray(2)) # inplace add b += bytearray(3) print(b) # extend b.extend(bytearray(4)) print(b) # this inplace add tests the code when the buffer doesn't need to be increased b = bytearray() b += b"" # extend a bytearray from itself b = bytearray(b"abcdefgh") for _ in range(4): c = bytearray(b) # extra allocation, as above b.extend(b) print(b)