class?Rational(object): ????def?__init__(self,?p,?q): ????????self.p?=?p ????????self.q?=?q ????def?__add__(self,?r): ????????return?Rational(self.p?*?r.q?+?self.q?*?r.p,?self.q?*?r.q) ????def?__sub__(self,?r): ????????return?Rational(self.p?*?r.q?-?self.q?*?r.p,?self.q?*?r.q) ????def?__mul__(self,?r): ????????return?Rational(self.p?*?r.p?,?self.q?*?r.q) ????def?__div__(self,?r): ????????return?Rational(self.p?*?r.q?,?self.q?*?r.p) ????def?__str__(self): ????????if?self.p>self.q: ????????????miner=self.q ????????????maxer=self.p ????????else: ????????????miner=self.p ????????????maxer=self.q ????????a,b=judegement(miner,maxer) ????????if?self.p>self.q: ????????????return?'%s/%s'?%(b,a) ????????else: ????????????return?'%s/%s'?%(a,b) ????def?judgement(miner,maxer): ????????for?i?in?range(miner+1): ????????????if?maxer%i==0: ????????????????maxer=maxer/i ????????????????miner=miner/i ????????????????return?judegment(miner,maxer)? ????????return?miner,maxer ????__repr__?=?__str__ r1?=?Rational(1,?2) r2?=?Rational(1,?4) print?r1?+?r2 print?r1?-?r2 print?r1?*?r2 print?r1?/?r2題目是：Rational類雖然可以做加法，但無法做減法、乘方和除法，請繼續完善Rational類，實現四則運算。自己想的化簡過程哪出錯啊~，幫我看看，謝謝慕友啦