Script for snapping feature classes in 2 different feature datasets

I have 2 Feature Datasets in a geodatabase. One dataset contains bus routes and the other contains bus stops for each route. I want to create a script that will snap the bus stops to the vertex of the relevant bus route. There are over 100 routes and stops. They are stored in each dataset in order. They are named like this S102, S104 etc. for stops and B102, B104 for routes. I'm unsure about how to do a for loop that will get a stop and then get the right bus route