Python Doublets Adapter via GraphQL client - Complete Implementation

[konard]

🎯 Summary

This PR implements a complete solution for issue #15, providing a Python Doublets Adapter via GraphQL client with native Python interface for Doublets operations.

Fixes #15

✨ Key Features

• 🐍 Native Python API: Intuitive CRUD operations following Python conventions
• 🔌 Pluggable Architecture: Support for GraphQL, native C++ library, and custom backends
• 📊 GraphQL Client: Separate low-level GraphQL client for direct usage
• 🎨 Pythonic Interface: Support for iteration, len(), in operator, list comprehensions
• 🧪 Comprehensive Testing: Unit tests for all components with MockBackend
• 📚 Rich Documentation: Complete API reference and usage examples
• 📦 PyPI Ready: Proper package structure for publication

🏗️ Architecture

Core Components

1. Doublets: Main high-level interface providing native Python CRUD operations
2. DoubletsBackend: Abstract backend interface for extensibility
3. GraphQLBackend: Production backend using existing GraphQL server
4. MockBackend: In-memory backend for testing and development
5. DeepClient: Low-level GraphQL client (maintains backward compatibility)
6. Link: Data structure representing a doublet

Pluggable Design

The architecture supports swapping backends without changing client code:

# Start with GraphQL
doublets = Doublets(GraphQLBackend('http://server/graphql'))

# Later switch to native C++ library (when available)
# doublets._backend = NativeBackend('/path/to/library.so')

# Same API works with any backend
link = doublets.create(source=1, target=2)

🚀 Usage Examples

Basic CRUD Operations

from deepclient import Doublets, MockBackend

# Create a Doublets instance 
doublets = Doublets(MockBackend())

# Create links
link1 = doublets.create()  # Self-referencing link
link2 = doublets.create(source=1, target=2)  # Link from 1 to 2

# Search and iterate
for link in doublets:
    print(f"Link: {link}")

# Pythonic features
total = len(doublets)
if 42 in doublets:
    print("Link 42 exists")

# Search by criteria
links_from_1 = doublets.search(source=1)
count = doublets.count(target=2)

GraphQL Backend

from deepclient import Doublets, GraphQLBackend

# Connect to GraphQL server
doublets = Doublets(GraphQLBackend(
    'http://localhost:60341/v1/graphql',
    headers={'Authorization': 'Bearer token'}  # Optional
))

# Same API works with real GraphQL backend
new_link = doublets.create(source=1, target=2)
recent_links = doublets.search(limit=10)

📁 File Structure

python/
├── deepclient/
│   ├── __init__.py          # Main package exports
│   ├── doublets.py          # Core Doublets interface & Link class
│   ├── backends.py          # Backend implementations
│   ├── client.py            # GraphQL client (updated)
│   └── exceptions.py        # Error classes
├── examples/
│   ├── basic_usage.py       # Basic operations demo
│   └── custom_backend.py    # Custom backend examples
├── tests/
│   ├── test_doublets.py     # Comprehensive tests
│   └── test_client.py       # Original client tests (updated)
├── setup.py                 # Updated for PyPI
└── README.md                # Complete documentation

🧪 Test Results

All core functionality tested successfully:

• ✅ MockBackend CRUD operations
• ✅ Doublets high-level interface
• ✅ Pythonic features (iteration, len, contains)
• ✅ Search and filtering
• ✅ Graceful degradation without GraphQL dependencies
• ✅ Example scripts execution

🔄 Backward Compatibility

• Original DeepClient interface preserved
• Existing GraphQL functionality unchanged
• Optional GraphQL dependencies (graceful degradation)

🎯 Future Development

The architecture is designed to support the future native C++ backend mentioned in the issue:

# Future usage (when C++ library is ready)
from deepclient import NativeBackend

doublets = Doublets(NativeBackend('/path/to/doublets.so'))
# Same API, better performance

📋 Testing

# Core functionality (no external dependencies)
cd python && python3 -c "import deepclient; print('✓ Import successful')"

# Run examples
cd python && PYTHONPATH=. python3 examples/basic_usage.py

# Full test suite (requires pytest)
pip install pytest && python -m pytest tests/

💡 Implementation Notes

• Graceful degradation: Package works without GraphQL dependencies
• Type safety: Full type hints throughout
• Error handling: Proper exception hierarchy
• Performance: Efficient search and iteration
• Extensibility: Easy to add new backends

This implementation fully addresses the requirements in issue #15:

1. ✅ Standard Doublets CRUD operations API - Complete CRUD interface
2. ✅ Native Python code style - Pythonic patterns and conventions
3. ✅ Swappable GraphQL/native library - Pluggable backend architecture
4. ✅ Separate GraphQL client layer - DeepClient available independently
5. ✅ PyPI package ready - Updated setup.py and structure

🤖 Generated with Claude Code