save project

sbstr.py

+class Car:
+    def __init__(self,make,model):
+        self.make = make
+        self.model = model
+    def output_car(self):
+        print("这辆车是",self.make,"的",self.model)
+class dCar(Car):
+    
+    def __init__(self,make,model,bs):
+        super().__init__(make,model)
+        self.bs=bs
+    def opbs(self):
+        print("这辆汽车还有",self.bs,"千瓦时的电量")
+sb=dCar("比亚迪","秦",47648473654876)
+sb.opbs()
+sb.output_car()
+

sdstr.py

+class sdstr:
+    def __init__(self,money,rate,n):
+        self.money = money
+        self.rate = rate
+        self.n = n
+    def pay(self):
+        sbstr=self.rate/1200
+        sqstr=1-(1+sbstr)**(-12*self.n)
+        sxstr=sbstr/sqstr*self.money
+        print(format(sxstr,'.2f'))
+dsbstr=sdstr(500000,5.6,20)
+dsbstr.pay()
+