InvalidDocument: Unable to encode object: ObjectId ('51861bc79bb6550f2b98be23')

Question

I have been using mongo for a long time (with python, mongo 2.4.4 64 bit, OS X 10.8.2, pymongo 2.5.2, python 2.7.2) and I have observed strange behavior. Sometimes when you try to insert a document into the collection, the following exception occurs:

Unable to encode object: ObjectId ('51861bc79bb6550f2b98be23')

... "/Users/nutrina/www/env_pdf_admin_apache/lib/python2.7/site-packages/pymongo/collection.py", line 266, in save return self.insert (to_save, manipulate, safe, check_keys, ** kwargs) File "/Users/nutrina/www/env_pdf_admin_apache/lib/python2.7/site-packages/pymongo/collection.py", line 357, insert continue_on_error, self .__ uuid_subtype), safe) InvalidDocument: cannot encode object: ObjectId ('51861bc79bb6550f2b98be23')

I have no idea why this is happening. Has anyone else come across this error, or someone has an idea of ​​what might cause this?

Update: The object I'm trying to save has the following structure:

{ 'is_open': true, // boolean 'data': { 'user_id': ObjectId(...), // ObjectId 'user_type': 1, // Integer } } 

The error is indicated in the * user_id * field, but I am sure that the value is a valid ObjectId. This is the "_id" of the object (user) from another collection (users). And the save operation succeeds in the same value most of the time.

Thanks Gerald

Answer 1

Python integers are stored as arbitrary precision numbers that are not supported by Mongodb. First you need to convert them to regular int64 or string objects.

Answer 2

If you are not using your own type in your document (string, integer, date, boolean, etc.), you need to make sure that it is encoded correctly. If you incorrectly encode non-standard data types, do not guarantee that they can be inserted into PyMongo. You are probably facing an edge case when he refuses to build a new object in a PyMongo document.

PyMongo: Custom Types