CODEWITHSUNDEEP
pythondjangomongodbpymongo
user1336024
user1336024

Reputation: 43

Django MongoDB Engine DebugCursor "not JSON serializable"

Trying to serialize a MongoDB cursor in Django

import json
from pymongo import json_util

results = json.dumps(results, default=json_util.default, separators=(',', ':'))

Where the original results is something like

[{u'_id': ObjectId('4f7c0f34705ff8294a00006f'),
  u'identifier': u'1',
  u'items': [{u'amount': 9.99, u'name': u'PapayaWhip', u'quantity': 1}],
  u'location': None,
  u'timestamp': datetime.datetime(2012, 4, 4, 10, 7, 0, 596000),
  u'total': 141.25}]

Edit: Obtained by using something like

from django.db import connections

connection = connections['default']

results = connection.get_collection('papayas_papaya')
results = results.find({
    'identifier': '1',
})

Gives me

TypeError: <django_mongodb_engine.utils.DebugCursor object> is not JSON serializable

Does anyone know what I'm doing wrong?

Using json_util should serialize MongoDB documents, maybe my issue is that I'm trying to serliaze a cursor. (How do I get the document from the cursor? A simple tuple "cast"?)

Cheers!

Upvotes: 4

Views: 1289

Answers (2)

Jonas H.
Jonas H.

Reputation: 2491

You should really be using Django's serialization system, or a pluggable JSON-serialization app at least.

Upvotes: 0

Nolen Royalty
Nolen Royalty

Reputation: 18653

Are you trying to serialize just one piece of data? If so, just change

results = results.find({
    'identifier': '1',
})

to

results = results.find_one({
    'identifier': '1',
})

(Although you really should make a distinction between your results and the variable representing your collection.)

If you are trying to serialize multiple pieces of data, you can keep the find and then iterate through the cursor and serialize each piece of data.

serialized_results = [json.dumps(result, default=json_util.default, separators=(',', ':')) for result in results]

Upvotes: 5

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