cover mongoengine document to raw dict

mongoengine_utils.py

from bson.objectid import ObjectId
from bson.dbref import DBRef
from mongoengine.document import Document
import collections
from datetime import datetime
from mongoengine.queryset import QuerySet

def raw_data(data):

    if isinstance(data, unicode):
        return data.encode('utf-8')
    elif isinstance(data, str):
        return data
    elif isinstance(data, QuerySet):
        return raw_data([i for i in data])
    elif isinstance(data, datetime):
        return data.strftime('%s000')
    elif isinstance(data, ObjectId):
        return str(data)
    elif isinstance(data, Document):
        data.select_related()
        return raw_data(data.__dict__.get('_data'))
    elif isinstance(data, collections.Mapping):
        return dict(map(raw_data, data.iteritems()))
    elif isinstance(data, collections.Iterable):
        return type(data)(map(raw_data, data))
    else:
        return data