Python: Find equivalent surrogate pair from non-BM

问题:

The answer presented here: How to work with surrogate pairs in Python? tells you how to convert a surrogate pair, such as '\ud83d\ude4f' into a single non-BMP unicode character (the answer being "\ud83d\ude4f".encode('utf-16', 'surrogatepass').decode('utf-16')). I would like to know how to do this in reverse. How can I, using Python, find the equivalent surrogate pair from a non-BMP character, converting '\U0001f64f' (