Implementing aggregation in Mongo using PyMongo
We have already seen PyMongo using Python's client interface for Mongo in previous recipes. In this recipe, we will use the postal codes collection and run an aggregation example using PyMongo. The intention of this recipe is not to explain aggregation but to show how aggregation can be implemented using PyMongo. In this recipe, we will aggregate the data based on the state names and get the top five state names by the number of documents that they appear in. We will make use of the $project, $group, $sort, and $limit operators for the process.
Getting ready
To execute the aggregation operation, we need to have a server up and running. A simple single node is what we need. Refer to the Installing single node MongoDB recipe from Chapter 1, Installing and Starting the Server for instructions on how to start the server. The data that we will operate on needs to be imported in the database. The steps to import the data are mentioned in the Creating...
