Python FastAPI Dependency Injection vs Global Singletons for Database Sessions
In FastAPI, create database sessions per request through a dependency, and keep only the engine or connection pool as a shared object. A single global session...
Search
99 results for "Python"
Python Dataclass vs Pydantic Models for Domain Objects
Dataclasses naturally describe internal Python state while validation models help parse external representations. Production-ready design starts with the...
Python Async Generators and Resource Cleanup in Streaming APIs
Async generators may retain cursors and network connections while consumers await the next item. Production-ready design starts with the behavior that must...
Python SQLAlchemy Session Lifecycles for Concurrent Web Requests
A SQLAlchemy session represents mutable unit-of-work state and should not be shared across concurrent requests. Production-ready design starts with the...
Python Celery Task Retries and Idempotency for Payment Workflows
At-least-once task execution may repeat payment operations after timeout or worker interruption. Begin with a concrete correctness contract: what users can...
Python Pydantic Strict Validation vs Coercion at API Boundaries
Type coercion can make an API convenient but may silently accept unintended representations. Begin with a concrete correctness contract: what users can...
Python Structured Concurrency and Cancellation for Web APIs
Structured concurrency keeps child task lifetimes inside a parent operation. Begin with a concrete correctness contract: what users can observe, which...
Python Database Transaction Boundaries in Web Services
Short transactions reduce lock contention and make recovery more predictable. Begin with requirements and the workload. Record what users expect, what can...
Python Type Checking Protocols vs Abstract Base Classes
Protocols express structural contracts; abstract base classes require inheritance for their nominal contracts. Begin with requirements and the workload. Record...