Python的初学者程序员

Question

寻求帮助来解决这个问题，我认为问题在于第 7 行添加了两个值。不幸的是，我没有太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

你不能只是将两个Apple实例加在一起，因为它没有定义，但你可以把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，但这实现起来要高级一些：

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

试试这个：

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