# Advanced Python Tools Research (2025)

## Executive Summary

Research on cutting-edge Python development tools for architecture enforcement, type checking, and code quality. Focus on tools that complement ultra-strict Python templates.

## 1. Deply - Architecture Enforcement

**GitHub**: https://github.com/Vashkatsi/deply  
**Stars**: 164  
**Status**: v0.8.0 (stable)  
**Downloads**: >2k/month  
**Coverage**: 85%  
**Python**: 3.8+

### What It Does
- Static code analysis for Python architecture
- Enforces architectural patterns and dependencies
- Visualizes layers and violations with Mermaid diagrams
- Prevents circular dependencies and layer violations

### Key Features
- **Layer-Based Analysis**: Define project layers and restrict dependencies
- **Dynamic Collectors**: File patterns, class inheritance, regex matching
- **Cross-Layer Rules**: Disallow specific layer dependencies
- **Mermaid Visualization**: Generate architecture diagrams
- **Error Suppression**: Inline comments to suppress violations
- **Parallel Analysis**: Fast processing of large codebases
- **Custom Collectors**: Extensible system for custom rules

### Configuration Example
```yaml
deply:
  layers:
    - name: models
      collectors:
        - type: class_inherits
          base_class: "django.db.models.Model"
    - name: views
      collectors:
        - type: file_regex
          regex: ".*/views_api.py"
  ruleset:
    views:
      disallow_layer_dependencies:
        - models
```

### Performance
- **10x Performance Boost** in v0.5.1
- Parallel file analysis
- Efficient dependency graph computation

### Roadmap
- ✅ Parallel analysis
- ✅ Custom collectors
- ✅ Error suppression
- 🔲 Interactive setup wizard
- 🔲 GitHub Actions templates
- 🔲 Framework presets (FastAPI/Django/Flask)
- 🔲 Custom rules system

## 2. Pyrefly - Fast Type Checker

**GitHub**: https://github.com/facebook/pyrefly  
**Website**: https://pyrefly.org/  
**Creator**: Meta Platforms  
**Status**: Beta Release

### Performance Metrics
- **1.85M lines/second** type checking speed
- **10-100x faster** than mypy
- **20-200x faster** than Zuban (in some cases)
- Uses multi-threading for maximum performance

### Features
- Lightning-fast autocomplete
- Instant error feedback in IDE
- PyRight-like strict mode
- Language server protocol support
- VSCode extension available

### Comparison
| Tool | Speed | Memory | Mode |
|------|-------|--------|------|
| Pyrefly | 1.85M lines/s | Optimized | Strict |
| Pyright | Slower | Higher | Strict |
| MyPy | Much slower | Higher | Strict |
| Zuban | 20-200x slower | Half | PyRight-like |

## 3. Zuban - Alternative Type Checker

**Status**: Beta Release  
**Performance**: 20-200x faster than MyPy  
**Memory**: ~50% of Ty/Pyrefly  
**Modes**: PyRight-like + custom

## 4. Integration Strategy for TraceRTM

### Recommended Stack
```
Code Quality Pipeline:
├── Ruff (linting/formatting) ✅ Already using
├── MyPy/basedpyright (type checking) ✅ Already using
├── Deply (architecture enforcement) 🆕 RECOMMENDED
├── Pyrefly (fast type checking) 🆕 OPTIONAL
└── Coverage (test coverage) ✅ Already using
```

### Implementation Priority

**Phase 1 (Immediate)**
- Add Deply for architecture enforcement
- Define layers: config, models, services, api, utils
- Create deply.yaml configuration
- Add to CI/CD pipeline

**Phase 2 (Short-term)**
- Integrate Pyrefly for faster type checking
- Set up VSCode extension
- Configure language server

**Phase 3 (Medium-term)**
- Add framework presets when available
- Implement custom collectors
- Create architecture documentation

## 5. Deply Configuration for TraceRTM

```yaml
deply:
  paths:
    - src/tracertm
  
  exclude_files:
    - ".*/__pycache__/.*"
    - ".*\\.venv/.*"
  
  layers:
    - name: config
      collectors:
        - type: file_regex
          regex: ".*/config/.*"
    
    - name: models
      collectors:
        - type: file_regex
          regex: ".*/models/.*"
    
    - name: services
      collectors:
        - type: class_name_regex
          class_name_regex: ".*Service$"
    
    - name: api
      collectors:
        - type: file_regex
          regex: ".*/api/.*"
    
    - name: utils
      collectors:
        - type: file_regex
          regex: ".*/utils/.*"
  
  ruleset:
    api:
      disallow_layer_dependencies:
        - models
    services:
      disallow_layer_dependencies: []
    models:
      disallow_layer_dependencies:
        - api
        - services
```

## 6. Benefits for TraceRTM

✅ **Enforce Clean Architecture**: Prevent circular dependencies  
✅ **Modularity**: Ensure independent, reusable modules  
✅ **Scalability**: Maintain architecture as codebase grows  
✅ **Documentation**: Visualize architecture with Mermaid  
✅ **CI/CD Integration**: Catch violations in pull requests  
✅ **Team Alignment**: Clear architectural rules for team  

## 7. Next Steps

1. Install Deply: `pip install deply`
2. Create deply.yaml configuration
3. Run analysis: `deply analyze`
4. Generate diagram: `deply analyze --mermaid`
5. Integrate into CI/CD
6. Document architectural rules

## References

- Deply: https://github.com/Vashkatsi/deply
- Deply Docs: https://vashkatsi.github.io/deply
- Pyrefly: https://pyrefly.org/
- Zuban: Beta release (2025)

