Django:获取外键类型

是否有方法获取与我的密钥相关的型号的外键类型?目前,我正在尝试以下方法:

def __init__(self, *args, **kwargs):
        super(JobOrderSupplementForm, self).__init__(*args, **kwargs)
        for field in self.fields:
            if type(self.fields[field]) == TypedChoiceField:
                fieldOption = <Whatever type key points to>.get(id=self.__dict__['initial'][field])
                if not fieldOption.isActive:
                    ...Do something to the choices...

self.fields[field].__dict__['coerce']
>>> <bound method ForeignKey.to_python of <django.db.models.fields.related.ForeignKey object at 0x01609EF0>>

任何帮助都将不胜感激。