Constitution: eo_lib¶

1. Vision statement¶

To provide a robust, enterprise-grade, and strictly architectural Python library for CRUD operations that can be seamlessly imported into larger applications. It serves as a canonical example of "Correct" Software Engineering principles applied to Python.

2. Core Values & Principles¶

DRY (Don't Repeat Yourself): Domain Entities and ORM Models are ONE and the SAME. No duplicate class definitions.
TDD (Test Driven Development): All features must be defined by tests first. Code is only written to pass tests.
Full Documentation: Every class and method must have a docstring explaining its purpose, arguments, and return values.
Layered Architecture: MVC + Service + Repository is preserved, but Entities flow through all layers (Unified Model).
SOLID: Adherence to principles where they don't conflict with Pragmatism (DRY).
Module-First Structure: Every folder is a Python module and must contain an __init__.py. This file must expose public classes to flatten the import path (e.g., from package import Class instead of from package.file import Class).

3. Technology Stack¶

Language: Python 3.10+
Database: PostgreSQL (SQLAlchemy Sync)
Testing: Pytest
Validation: Pydantic (Optional, or handled via Type Hints/Pre-conditions)

4. Architecture Overview¶

Controller Layer: Public Interface / Facade.
Service Layer: Pure Business Logic.
Domain/Model Layer: Unified SQLAlchemy Models (Active Record style definitions, but unrelated to persistence logic).
Infrastructure Layer: Repositories handling DB sessions.

5. Methodology¶

Spec-Driven Development: Requirements -> Specs -> SDD -> Code.