如何对ModelForm中的ChoiceField进行排序？

from django.forms import ChoiceField

class SortedChoiceField(ChoiceField):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.choices = sorted(self.choices, key=lambda x: x[1])

from django import forms
from .models import YourModel

class YourModelForm(forms.ModelForm):
    your_choice_field = SortedChoiceField(choices=YourModel.CHOICES)

    class Meta:
        model = YourModel
        fields = ['your_choice_field']