pyramid_mongo is intended for use with the default python driver for mongodb
You have to define at least 3 things in your settings
mongo.uri = uri of your database (mongodb://localhost/) mondo.db = name of the database you want to use
Those two are optional
mongo.username.dbname = username for authentication to dbname mongo.password.dbname = password used for authentication to dbname
The format of the mongodb uri is the one that use mongodb. You can pass multiple uris to mongo.uri. They must be separated by newlines and they must be uniques. MongoDb will not accept two identical uri. But it will accept uris reffering to the same host and same server if hostnames are not identical.
mongo.uri = localhost 127.0.0.1
Is something valid and will work. Connection will open 2 connections on the default port.