Python Patterns

---
name: python-patterns
description: Python development principles and decision-making.
category: development
version: 4.1.0-fractal
layer: master-skill
---

# Python Patterns

> Python development principles and decision-making for 2025.
> **Learn to THINK, not memorize patterns.**

---

## ⚠️ How to Use This Skill

This skill teaches **decision-making principles**, not fixed code to copy.

- ASK user for framework preference when unclear
- Choose async vs sync based on CONTEXT
- Don't default to same framework every time

---

## 1. Framework Selection (2025)

## 🧠 Knowledge Modules (Fractal Skills)

### 1. [Decision Tree](./sub-skills/decision-tree.md)
### 2. [Comparison Principles](./sub-skills/comparison-principles.md)
### 3. [Selection Questions to Ask:](./sub-skills/selection-questions-to-ask.md)
### 4. [When to Use Async](./sub-skills/when-to-use-async.md)
### 5. [The Golden Rule](./sub-skills/the-golden-rule.md)
### 6. [Async Library Selection](./sub-skills/async-library-selection.md)
### 7. [When to Type](./sub-skills/when-to-type.md)
### 8. [Common Type Patterns](./sub-skills/common-type-patterns.md)
### 9. [Pydantic for Validation](./sub-skills/pydantic-for-validation.md)
### 10. [Structure Selection](./sub-skills/structure-selection.md)
### 11. [FastAPI Structure Principles](./sub-skills/fastapi-structure-principles.md)
### 12. [Django Async (Django 5.0+)](./sub-skills/django-async-django-50.md)
### 13. [Django Best Practices](./sub-skills/django-best-practices.md)
### 14. [async def vs def in FastAPI](./sub-skills/async-def-vs-def-in-fastapi.md)
### 15. [Dependency Injection](./sub-skills/dependency-injection.md)
### 16. [Pydantic v2 Integration](./sub-skills/pydantic-v2-integration.md)
### 17. [Selection Guide](./sub-skills/selection-guide.md)
### 18. [When to Use Each](./sub-skills/when-to-use-each.md)
### 19. [Exception Strategy](./sub-skills/exception-strategy.md)
### 20. [Error Response Philosophy](./sub-skills/error-response-philosophy.md)
### 21. [Testing Strategy](./sub-skills/testing-strategy.md)
### 22. [Async Testing](./sub-skills/async-testing.md)
### 23. [Fixtures Strategy](./sub-skills/fixtures-strategy.md)
### 24. [❌ DON'T:](./sub-skills/dont.md)
### 25. [✅ DO:](./sub-skills/do.md)