如何在python中正确编写示例元素

def add_numbers(a, b):
    return a + b

class Rectangle:
    def __init__(self, width, height):
        self.width = width
        self.height = height
    
    def area(self):
        return self.width * self.height

score = 85

if score >= 90:
    grade = 'A'
elif score >= 80:
    grade = 'B'
elif score >= 70:
    grade = 'C'
else:
    grade = 'D'

print("学生等级：", grade)

fruits = ['apple', 'banana', 'orange']

for fruit in fruits:
    print(fruit)

try:
    result = 10 / 0
except ZeroDivisionError:
    print("除零错误发生")