Python3 to Arduino

[holt24]

Hi. My first post on here.
 I am trying to send - receive Python3 <> Arduino.
I had this working with Python2.7 now would like to convert to Pyhon3.
python2.7 code that worked.

    ser.write('<')
    ser.write(RorD)
    ser.write('>')

python3 code

    ser.write(bytes(b'<'))
    ser.write(b'RorD')
    ser.write(bytes(b'>'))

I think the Arduino is now receiving b'<'
RorB is a int.

Arduino snip

char startMarker = '<';
char endMarker = '>';

How can I send just '<'
Thanks for any help.
Hope I used the python tag right.