如何在django中将日期字符串传递到datetime字段？

from datetime import datetime

date_string = "2022-12-31"
date_format = "%Y-%m-%d"
date_object = datetime.strptime(date_string, date_format)

from django.db import models

class MyModel(models.Model):
    date_field = models.DateTimeField()

my_model = MyModel()
my_model.date_field = date_object