This repo folder is the corresponding Python 2 and 3 code to the Module 19 codelab. The tutorial STARTs with the Python 2 code in the Module 18 repo folder and leads developers through its migration from pull tasks via App Engine taskqueue to Cloud Pub/Sub, culminating in the code in this folder. The code is both Python 2 and 3 compatible, and either uncomment the Python 3 runtime in app.yaml and delete all other lines, or just use app3.yaml, delete appengine_config.py and any lib folder. The migration from App Engine ndb to Cloud NDB, covered in Module 2, also takes place.