Python入门程序员

Question

寻求帮助以解决此问题，我认为问题在于第7行将两个值相加。不幸的是，我没有很多运气解决这个问题。任何帮助，将不胜感激。

谢谢。

class Apple:
    def __init__(self, number_of_seeds):
        self.number_of_seeds = number_of_seeds

green_apple = Apple(number_of_seeds=10)
red_apple = Apple(number_of_seeds=20)
print(f'{green_apple + red_apple}')

Answer 1

您不能只将两个Apple实例加在一起，因为这没有定义，但是您可以将Apple.number_of_seeds加在一起，因为这只是整数加法。例如：

class Apple:
    def __init__(self, number_of_seeds):
        self.number_of_seeds = number_of_seeds

green_apple = Apple(number_of_seeds=10)
red_apple = Apple(number_of_seeds=20)
print (red_apple.number_of_seeds + green_apple.number_of_seeds)
# 30

或者，您可以定义打印方法（__str__或__repr__）和__add__方法，但是实现起来有点先进：

class Apple:
    def __init__(self, number_of_seeds):
        self.number_of_seeds = number_of_seeds
    def __add__(self, other_apple):
        self.number_of_seeds += other_apple.number_of_seeds
        return self.number_of_seeds
    def __repr__(self):
        return str(self.number_of_seeds)

green_apple = Apple(number_of_seeds=10)
red_apple = Apple(number_of_seeds=20)
print(f'{green_apple + red_apple}')
# 30

Answer 2

尝试一下：

green_apple=Apple(10)
red_apple=Apple(20)