After 4.5.4 the return types for rvec and tvec in cv2.calibrateCamera are tuples. Previously they were lists. Our code relied on being able to change the values of tvec and rvec but tuples are immutable. It’s easily fixed in our code by converting them, but I was wondering if anyone could point me to where the return types are defined. The documentation refers to cv::OutputArrayOfArrays but I can’t work out how that relates to lists and tuples in Python.