python - Django Rest Framework - 如何重组 json 响应？

Question

我正在使用 Django Rest Framework(连同 rest_framework_mongoengine)并覆盖我的序列化程序的 to_representation() 以发回我自己的自定义 JSON 对象。一切正常，但 JSON 字段的顺序困惑了。请告诉我如何重新排序/重组被发回的 JSON 对象。序列化程序如下所示:

class PharmacySerializer(DocumentSerializer):
    bank_account = serializers.DictField(child=serializers.CharField(), required=False)

    class Meta:
        model = Pharmacy
        fields = (
            'id', 'name', 'email', 'mobile', 'address_line_1', 'address_line_2',
            'city', 'state', 'zip', 'created_by', 'created_on', 'last_updated_by', 'license_number',
            'bank_account', 'last_updated_on', 'is_email_verified', 'is_mobile_verified', 'is_active')
        read_only_fields = ('created_by', 'created_on', 'last_updated_by', 'last_updated_on', 'is_active')

    def to_representation(self, pharmacy):
        return {
            'id': str(pharmacy.id),
            'name': pharmacy.name,
            'email': pharmacy.email,
            'mobile': pharmacy.mobile,
            'address_line_1': pharmacy.address_line_1,
            'address_line_2': pharmacy.address_line_2,
            'city': pharmacy.city,
            'state': pharmacy.state,
            'zip': pharmacy.zip,
            'created_by': pharmacy.created_by,
            'created_on': pharmacy.created_on,
            'last_updated_by': pharmacy.last_updated_by,
            'license_number': pharmacy.license_number,
            'bank_account': {
                'bank_name': pharmacy.bank_account.bank_name,
                'account_number': pharmacy.bank_account.account_number,
                'account_type': pharmacy.bank_account.account_type
            },
            'last_updated_on': pharmacy.last_updated_on,
            'is_email_verified': pharmacy.is_email_verified,
            'is_mobile_verified': pharmacy.is_mobile_verified,
            'is_active': pharmacy.is_active
        }

我得到的回应是:

[
    {
        "city": "City",
        "name": "Some Pharmacy",
        "zip": "778372",
        "mobile": "9880082229",
        "license_number": "SP22",
        "is_mobile_verified": false,
        "is_active": true,
        "created_on": "2016-06-18T19:01:02.901",
        "created_by": null,
        "email": "somepharmacy@gmail.com",
        "state": "State",
        "last_updated_by": null,
        "is_email_verified": false,
        "last_updated_on": "2016-06-18T19:01:02.901",
        "address_line_2": null,
        "id": "57659a6ea3b6561c0f20265e",
        "bank_account": {
            "bank_name": "HSBC",
            "account_type": "Savings",
            "account_number": "663822553"
        },
        "address_line_1": "Address"
    }
]

我希望它与 to_representation() 的返回字典的顺序相同

Answer 1

如果你想保持响应键的顺序，你可以使用 OrderedDict.但是关于 OrderedDicts，您应该记住一件事:

OrderedDict 仅在插入键时保持顺序。使用 kwargs 初始化时订单丢失。

来自 Python docs:

The OrderedDict constructor and update() method both accept keyword arguments, but their order is lost because Python’s function call semantics pass-in keyword arguments using a regular unordered dictionary.

您需要先创建一个OrderedDict实例，然后一个一个地添加键。

from collections import OrderedDict

def to_representation(self, pharmacy):
    ret = OrderedDict() # initialize on ordereddict

    # insert keys one by one in desired oreder
    ret['id'] = str(pharmacy.id)
    ret['name'] = pharmacy.name
    ret['email'] = pharmacy.email
    ret['mobile'] = pharmacy.mobile
    ret['address_line_1'] = pharmacy.address_line_1
    ret['address_line_2'] = pharmacy.address_line_2
    ret['city'] = pharmacy.city
    ret['state'] = pharmacy.state
    ret['zip'] = pharmacy.zip
    ret['created_by'] = pharmacy.created_by
    ret['created_on'] = pharmacy.created_on
    ret['last_updated_by'] = pharmacy.last_updated_by
    ret['license_number'] = pharmacy.license_number
    ret['bank_account'] = {
        'bank_name' = pharmacy.bank_account.bank_name
        'account_number' = pharmacy.bank_account.account_number
        'account_type' = pharmacy.bank_account.account_type
    }
    ret['last_updated_on'] = pharmacy.last_updated_on
    ret['is_email_verified'] = pharmacy.is_email_verified
    ret['is_mobile_verified'] = pharmacy.is_mobile_verified
    ret['is_active'] = pharmacy.is_active

    return ret

注意:另一种选择(推荐)是使用EmbeddedDocumentSerializer对于 bank_account 字段。 那么您将不需要覆盖 to_representation() 方法。