如何使Django slugify与Unicode字符串正常工作？

pip install django-slugify

INSTALLED_APPS = [
    # ...
    'slugify',
    # ...
]

from django.db import models
from slugify import slugify

class MyModel(models.Model):
    my_field = models.CharField(max_length=255)
    slug = models.CharField(max_length=255, unique=True, blank=True)

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.my_field)
        super(MyModel, self).save(*args, **kwargs)