如何在同一django模型的另一个值中使用模型的值

from django.db import models

class MyModel(models.Model):
    field1 = models.CharField(max_length=100)
    field2 = models.CharField(max_length=100, blank=True)

    def save(self, *args, **kwargs):
        self.field2 = self.field1  # 在保存模型时，将field1的值赋给field2
        super().save(*args, **kwargs)

python manage.py makemigrations
python manage.py migrate

my_model = MyModel()
my_model.field1 = "Hello"
my_model.save()

print(my_model.field2)  # 输出：Hello