Guido, when you approved this did you intend for the numeric tower to be amended as well?  We elected not to do so for as_integer_ratio() and the same choice should be made here (because it's hard to add methods to ABCs without breaking existing user classes registered to that ABC).

FWIW, it's not too late to change your mind about doing this at all. I don't see this as a feature in other languages and even the ultra thorough decimal arithmetic specification elected not to include this method.  The benefits are somewhat dubious but new method counts are certain:   len(dir(int)) == 72