加密django字段(不是密码)

from django.db import models
from cryptography.fernet import Fernet

# 生成密钥并保存到安全位置
key = Fernet.generate_key()
cipher_suite = Fernet(key)

class EncryptedField(models.CharField):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def from_db_value(self, value, expression, connection):
        if value is None:
            return value
        return cipher_suite.decrypt(value.encode()).decode()

    def to_python(self, value):
        if isinstance(value, str):
            return value
        if value is None:
            return value
        return cipher_suite.decrypt(value.encode()).decode()

    def get_prep_value(self, value):
        return cipher_suite.encrypt(value.encode()).decode()

class MyModel(models.Model):
    sensitive_data = EncryptedField(max_length=255)