Copper “Work hardens” if it is bent – so having cut the pipe to length, heat it to cherry red and immediately quench in cold water. The pipe with then be very soft (or ductile as R.M. would say!!!!).
If you need a tight bend, keep heating and quenching, although I’ve never found a copper petrol/oil pipe which will not form in one go. Use your thumbs and fingers, as any tool will mark the soft outer surface and set up a “kink-point” which will cause a flat.