Entry point: /faion-net — invoke this skill for automatic routing to the appropriate domain.Python Developer Skill
Python development specializing in Django, FastAPI, async programming, and modern Python patterns.
Purpose
Handles all Python backend development including Django full-stack apps, FastAPI async APIs, pytest testing, and Python best practices.
Context Discovery
Auto-Investigation
Gather Python project context before asking questions:
| Signal | How to Check | What It Tells Us |
|---|---|---|
manage.py | Glob("**/manage.py") | Django project |
pyproject.toml | Read("pyproject.toml") | Dependencies, Python version, tools |
requirements.txt | Read("requirements.txt") | Dependencies (legacy setup) |
settings/*.py | Glob("**/settings/*.py") | Django settings structure |
services/*.py | Glob("**/services/*.py") | Service layer exists → follow pattern |
conftest.py | Glob("**/conftest.py") | pytest fixtures exist → check style |
factories.py | Glob("**/factories.py") | Factory Boy used for tests |
tasks.py or celery.py | Glob("**/tasks.py") | Celery async tasks used |
.pre-commit-config.yaml | Glob("**/.pre-commit-config.yaml") | Pre-commit hooks, linting tools |
mypy.ini or pyproject.toml [tool.mypy] | Check for mypy config | Type checking enforced |
Read existing code to understand patterns:
- Read a model file to see BaseModel pattern
- Read a service file to see service layer style
- Read a test file to see testing conventions
- Read serializers to see DRF patternsDiscovery Questions
Use AskUserQuestion for Python-specific decisions not clear from investigation.
Q1: Framework Choice (only if not detected)
question: "Which Python framework are you using?"
header: "Framework"
multiSelect: false
options:
- label: "Django"
description: "Full-featured web framework with ORM"
- label: "FastAPI"
description: "Modern async API framework"
- label: "Flask"
description: "Lightweight microframework"
- label: "No framework (scripts/CLI)"
description: "Pure Python application"Routing:
- "Django" → django-* methodologies
- "FastAPI" → python-fastapi, python-async
- "Flask" → python-web-frameworks
- "No framework" → python-basics, python-code-quality
Q2: Code Placement (for new code in Django)
question: "What type of code are you writing?"
header: "Code Type"
multiSelect: false
options:
- label: "Database operations (create/update/delete)"
description: "Code that modifies data"
- label: "Business logic (calculations, transformations)"
description: "Pure functions, no side effects"
- label: "API endpoint"
description: "HTTP request handling"
- label: "Background task"
description: "Async/scheduled processing"
- label: "Not sure"
description: "I'll help you decide based on what it does"Routing (Django decision tree):
- "Database operations" →
services/directory - "Business logic" →
utils/directory (pure functions) - "API endpoint" →
views/orviewsets/ - "Background task" →
tasks/with Celery - "Not sure" → Ask what the code does, apply decision tree
Q3: Async Requirements
question: "Does this need async/concurrent execution?"
header: "Async"
multiSelect: false
options:
- label: "Yes, I/O bound (API calls, file ops)"
description: "Multiple external calls that can run in parallel"
- label: "Yes, background processing"
description: "Long-running tasks that shouldn't block"
- label: "No, synchronous is fine"
description: "Simple request-response flow"
- label: "Not sure"
description: "I'll analyze and recommend"Routing:
- "I/O bound" → python-async, asyncio patterns
- "Background processing" → django-celery or FastAPI BackgroundTasks
- "Synchronous" → Standard patterns
- "Not sure" → Analyze task characteristics
Q4: Type Safety Level
question: "What level of type safety do you want?"
header: "Types"
multiSelect: false
options:
- label: "Strict (full type hints, mypy strict)"
description: "Maximum type safety, catch errors early"
- label: "Gradual (key interfaces typed)"
description: "Type public APIs, internal can be looser"
- label: "Minimal (match existing code)"
description: "Follow project's current style"Routing:
- "Strict" → python-type-hints strict mode, Protocol, TypedDict
- "Gradual" → Type annotations on public functions
- "Minimal" → Match existing codebase style
Q5: Testing Approach (for new features)
question: "How should we approach testing?"
header: "Testing"
multiSelect: false
options:
- label: "TDD (tests first)"
description: "Write tests before implementation"
- label: "Tests after implementation"
description: "Write tests once code works"
- label: "Match existing test coverage"
description: "Follow project's testing patterns"
- label: "No tests needed"
description: "Spike/prototype, tests later"Routing:
- "TDD" → tdd-workflow, write test first
- "Tests after" → django-pytest or python-testing-pytest
- "Match existing" → Read conftest.py, follow patterns
- "No tests" → Skip testing methodologies
When to Use
- Django projects (models, services, API, testing)
- FastAPI async APIs
- Python async patterns and concurrency
- Python type hints and strict typing
- Python testing with pytest
- Python code quality and tooling
Methodologies
| Category | Methodology | File |
|---|---|---|
| Django Core | ||
| Django standards | Django coding standards, project structure | django-coding-standards.md |
| Django models | Model design, base model patterns | django-base-model.md |
| Django models reference | Model fields, managers, migrations | django-models.md |
| Django services | Service layer architecture | django-services.md |
| Django API | DRF patterns, serializers, viewsets | django-api.md |
| Django testing | Django test patterns, factories | django-testing.md |
| Django pytest | pytest-django, fixtures, parametrize | django-pytest.md |
| Django celery | Async tasks, queues, beat | django-celery.md |
| Django quality | Code quality, linting, formatting | django-quality.md |
| Django imports | Import organization, circular imports | django-imports.md |
| Django decision tree | Framework selection, when to use Django | django-decision-tree.md |
| Django decomposition | Breaking down Django monoliths | decomposition-django.md |
| FastAPI | ||
| FastAPI basics | Routes, dependencies, validation | python-fastapi.md |
| Web frameworks | Django vs FastAPI vs Flask comparison | python-web-frameworks.md |
| Async Python | ||
| Async basics | asyncio, await, event loop | python-async.md |
| Async patterns | Concurrent patterns, asyncio best practices | python-async-patterns.md |
| Type Safety | ||
| Type hints | Gradual typing, annotations | python-type-hints.md |
| Python typing | TypedDict, Protocol, Generic | python-typing.md |
| Testing | ||
| pytest basics | Fixtures, parametrize, markers | python-testing-pytest.md |
| Python Core | ||
| Python basics | Language fundamentals, patterns | python-basics.md |
| Python overview | Quick reference | python.md |
| Python modern 2026 | Python 3.12/3.13 features | python-modern-2026.md |
| Python code quality | ruff, mypy, black, isort | python-code-quality.md |
| Poetry setup | Dependency management, pyproject.toml | python-poetry-setup.md |
Tools
- Frameworks: Django 5.x, FastAPI 0.1x, Flask
- Testing: pytest, pytest-django, pytest-asyncio, factory-boy
- Type checking: mypy, pyright
- Linting: ruff, flake8, pylint
- Formatting: black, isort
- Package management: poetry, pip-tools, uv
Related Sub-Skills
| Sub-skill | Relationship |
|---|---|
| faion-backend-developer | Database patterns (PostgreSQL, Redis) |
| faion-api-developer | REST/GraphQL API design |
| faion-testing-developer | Advanced testing patterns |
| faion-devtools-developer | Architecture patterns, code quality |
Integration
Invoked by parent skill faion-software-developer when working with Python code.
*faion-python-developer v1.0 | 24 methodologies*