Irfan Dayan Irfan Dayan - 4 months ago 38
JSON Question

TypeError: ObjectId('') is not JSON serializable

My response back from MongoDB after querying an aggregated function on document using Python, It returns valid response and i can print it but can not return it.

Error:

TypeError: ObjectId('51948e86c25f4b1d1c0d303c') is not JSON serializable


Print:

{'result': [{'_id': ObjectId('51948e86c25f4b1d1c0d303c'), 'api_calls_with_key': 4, 'api_calls_per_day': 0.375, 'api_calls_total': 6, 'api_calls_without_key': 2}], 'ok': 1.0}


But When i try to return:

TypeError: ObjectId('51948e86c25f4b1d1c0d303c') is not JSON serializable


It is RESTfull call:

@appv1.route('/v1/analytics')
def get_api_analytics():
# get handle to collections in MongoDB
statistics = sldb.statistics

objectid = ObjectId("51948e86c25f4b1d1c0d303c")

analytics = statistics.aggregate([
{'$match': {'owner': objectid}},
{'$project': {'owner': "$owner",
'api_calls_with_key': {'$cond': [{'$eq': ["$apikey", None]}, 0, 1]},
'api_calls_without_key': {'$cond': [{'$ne': ["$apikey", None]}, 0, 1]}
}},
{'$group': {'_id': "$owner",
'api_calls_with_key': {'$sum': "$api_calls_with_key"},
'api_calls_without_key': {'$sum': "$api_calls_without_key"}
}},
{'$project': {'api_calls_with_key': "$api_calls_with_key",
'api_calls_without_key': "$api_calls_without_key",
'api_calls_total': {'$add': ["$api_calls_with_key", "$api_calls_without_key"]},
'api_calls_per_day': {'$divide': [{'$add': ["$api_calls_with_key", "$api_calls_without_key"]}, {'$dayOfMonth': datetime.now()}]},
}}
])


print(analytics)

return analytics


db is well connected and collection is there too and I got back valid expected result but when i try to return it gives me Json error. Any idea how to convert the response back into JOSON. Thanks

Answer

You should define you own JSONEncoder and using it:

import json
from bson import ObjectId

class JSONEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, ObjectId):
            return str(o)
        return json.JSONEncoder.default(self, o)

JSONEncoder().encode(analytics)