Make two RSIs appear pseudo-randomly

hello~I have previously used the randomtime function code and could only achieve rendering times over a period of time area, but I now I have two RSIs, 200ms and 1000ms, how do I make it appear pseudo-randomly.
Looking forward to your help!

You could do the following

Begin Experiment

rsis = [200,1000]

Begin Routine

shuffle (rsis)
thisRSI=rsis[0]
thisExp.addData[‘RSI’,thisRSI]