Message 396790 - Python tracker

It may be helpful for the enum module to come with transitional functions like "pre310_str()" "pre310_repr()" "pre310_flag_str()" etc. so that people who are writing doctests that need to function on both < 3.10 and 3.10+ can temporarily do a "Enum.__str__ = pre310_str" in their test suites (and of course restore it later) until <=3.9 is no longer supported.  Otherwise everyone with doctest suites will be doing this ourselves.