如何在python中使用getattr获取django模型的外键对象的属性？

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

book = Book.objects.first()  # 假设已经获取到了Book模型的实例

# 使用getattr获取外键对象的属性
author_name = getattr(book.author, 'name', None)

print(author_name)  # 输出外键对象的name属性值