Convert mongodb return object to dictionary

问题

I'm using the bottle framework together with mongoengine. I have an orders model :

class OrderDetail(Option):
    orderDetailsQty = FloatField()

    def to_dict(self):
        return mongo_to_dict_helper(self)


class Order(Document):
    userName = StringField(required=True)
    orderDate = DateTimeField()
    orderStatus = ListField(EmbeddedDocumentField(Status))
    orderDetails = ListField(EmbeddedDocumentField(OrderDetail))
    orderComments = ListField(EmbeddedDocumentField(Comment))
    isActive = BooleanField()

    def to_dict(self):
        orderObj = mongo_to_dict_helper(self)
        orderDetailList = []
        for orderDetail in orderObj["orderDetails"]:
            orderDetailList.append(orderDetail.__dict__)
        orderObj["OrderDetails"] = orderDetailList
        return (self)

When mongodb is queried I get an object which is then converted in to a dict by using the following function :

def mongo_to_dict_helper(obj):
    return_data = []
    for field_name in obj._fields:
        if field_name in ("id",):
            continue
        data = obj._data[field_name]

        if isinstance(obj._fields[field_name], StringField):
            return_data.append((field_name, str(data)))
        elif isinstance(obj._fields[field_name], FloatField):
            return_data.append((field_name, float(data)))
        elif isinstance(obj._fields[field_name], IntField):
            return_data.append((field_name, int(data)))
        elif isinstance(obj._fields[field_name], ListField):
            return_data.append((field_name, int(data)))
        else:
            # You can define your logic for returning elements
            pass
    return dict(return_data)

I found this function after a long search in the internet. Later found out that this function also fails while defining a member as the ListField(EmbeddedDocumentField(obj)).

I also tried writing a condition for catching the specific case of EmbeddedDocumentField :

elif isinstance(obj._fields[field_name], EmbeddedDocumentField):
    return_data.append(mongo_to_dict_helper(data))

but that didn't do any good either.

Anyone have a workaround for this issue ?

回答1:

What about just using to_mongo method of an object to convert it to a dict?

object.to_mongo()

回答2:

Expanding on @alexvassel's and @z0r's answers, calling .to_mongo() converts the object to a SON instance. Once you have it, you can call its .to_dict() method to convert it to a dictionary.

For example... (qset is a queryset that's returned from mongoengine, after e.g. Posts.objects.all()).

sons = [ob.to_mongo() for ob in qset]
for son in sons:
    print str(son.to_dict())

回答3:

import json
json.loads(yourobj.to_json())

回答4:

combining all other answers,

import json
dict = {'data':[json.loads(ob.to_json()) for ob in qset]}

回答5:

you can custom method to convert object to dict

class Order(Document):
    userName = StringField(required=True)
    orderDate = DateTimeField()
    orderStatus = ListField(EmbeddedDocumentField(Status))
    orderDetails = ListField(EmbeddedDocumentField(OrderDetail))
    orderComments = ListField(EmbeddedDocumentField(Comment))
    isActive = BooleanField()

    def as_dict(self):
        return {
            "user_name": self.userName,
            "order_date": self.orderDate.strftime("%Y-%m-%d %H:%M:%S"),
        }

now you can use obj.as_dict() to dict

orders = Order.objects.all()
datas = [each.as_dict() for each in orders]

回答6:

Extending on @alexvassel's answer, to_mongo() method returns SON object, which you can convert to dict by calling its to_dict() method

object.to_mongo().to_dict()

来源：https://stackoverflow.com/questions/13230284/convert-mongodb-return-object-to-dictionary

标签

python

mongodb

python-2.7

bottle

mongoengine