Production means more than starting Python
A production application needs a supported runtime, controlled dependencies, secure configuration, database migration procedures, process management, logging, monitoring and a rollback strategy.
Development settings must not leak into production
Debug mode, development servers and verbose error pages are useful while building an application but can expose implementation details in production. Use the deployment method recommended for the chosen framework and hosting environment.
Prepare for failure
Plan health checks, backups, database migration safety, monitoring and rollback before the first serious release. A reliable deployment is one that can be observed and safely reversed.
Practice: write a production checklist covering runtime, dependencies, configuration, secrets, database changes, process management, logging, health checks and rollback.