class Person: def __init__(self, name, age,weight): self.name = name self.age = age self.weight = weight def __str__(self): return "{} age={} weight={}".format(self.name, self.age, self.weight) def gain_weight(self, by): ? p1=Person("yamada",20,55) print(p1) p1.gain_weight(3) print(p1) p1.gain_weight(1) print(p1) 出力 7-1 ✏ yamada age=20 weight=55 yamada age=20 weight=58 yamada age=20 weight=59

class Person:
    def __init__(self, name, age, weight):
        self.name = name
        self.age = age
        self.weight = weight
    def __str__(self):
        return "{} age={} weight={}".format(self.name, self.age, self.weight)
    def gain_weight(self, by):
        self.weight += by
    def loss_weight(self, by):
        self.weight -= by
p1=Person("yamada",20,55)
print(p1)
p1.gain_weight(3)
print(p1)
p1.gain_weight(1)
print(p1)