Using .sort with PyMongo

python mongodb pymongo
KennyPowers picture KennyPowers · Apr 20, 2012 · Viewed 38.5k times · Source

With PyMongo, when I try to retrieve objects sorted by their 'number' and 'date' fields like this:

db.test.find({"number": {"$gt": 1}}).sort({"number": 1, "date": -1})

I get this error:

TypeError: if no direction is specified, key_or_list must be an instance of list

What's wrong with my sort query?

Answer

georg picture georg · Apr 20, 2012

sort should be a list of key-direction pairs, that is

db.test.find({"number": {"$gt": 1}}).sort([("number", 1), ("date", -1)])

The reason why this has to be a list is that the ordering of the arguments matters and dicts are not ordered in Python < 3.6

Related questions

How to sort mongodb with pymongo

I'm trying to use the sort feature when querying my mongoDB, but it is failing. The same query works in the MongoDB console but not here. Code is as follows: import pymongo from pymongo import Connection connection = Connection() db = connection.…

Read More
How to update values using pymongo?

I've a mongodb collection in this form: {id=ObjectId(....),key={dictionary of values}} where dictionary of values is {'a':'1','b':'2'.....} Let dictionary of values be 'd'. I need to update the values of the key in …

Read More
How do I update a Mongo document after inserting it?

Let's say I insert the document. post = { some dictionary } mongo_id = mycollection.insert(post) Now, let's say I want to add a field and update it. How do I do that? This doesn't seem to work..... post = mycollection.find_one({"_…

Read More