import codecs
from io import IncrementalNewlineDecoder

data=b'\r\x00\n\x00z'

decoder = codecs.getincrementaldecoder("utf-16-le")("strict")
begin = decoder.decode(data[:2], False)
tail = decoder.decode(data[2:], False)
print("tail={0!r}".format(tail))

decoder = codecs.getincrementaldecoder("utf-16-le")("strict")
decoder = IncrementalNewlineDecoder(decoder, True)
begin = decoder.decode(data[:2], False)
tail = decoder.decode(data[2:], False)
print("tail={0!r}".format(tail))