I'm trying to try to report issues seen during MicroPython development, and which affect Python API in general, to CPython bug tracker. I submitted http://bugs.python.org/issue21180 and in response was pointed to http://legacy.python.org/dev/peps/pep-0467 "Improved API consistency for bytes and bytearray", which calls for deprecating bytes(3) syntax for creating zero-filled object of given size and instead introducing a factory method of bytes.zero(3). FYI.