The reason why you're getting each branch repeated twice is because aflowcplx reports on both ends of the line. This functionality is more useful when retrieving the flow, which might be different at each end. In the case of losses, it will look like repetition (since the loss of the line is not dependent on which side you're looking at).
The following two lines will give you the losses without repetition.
ierr, xarray = psspy.aflowcplx(-1,1,1,1,'PQLOSS')
xarray = [xarray[0][::2]]
The second line removes every second result.