Come usare
- Copia il comando e controlla il pacchetto prima di installarlo nel tuo ambiente agente.
- Controlla strumenti, credenziali e ambienti richiesti nel documento originale.
- Descrivi input e risultato desiderato; confronta l’output con le fonti.
npx skills add https://github.com/udaysharmadev/gravitas --skill gravitas-pythonPrima di iniziare
- L’installazione non include abbonamenti, quote API o accesso ai file.
- Stelle e installazioni indicano attività, non un test indipendente di qualità o sicurezza.
Documento Skill originale
Contenuto dal repository con titoli, esempi, codice, tabelle, link e immagini preservati.
GRAVITAS — Python Extension
Extends the base GRAVITAS skill with Python-specific patterns. Load skills/gravitas/SKILL.md first, then this file.
Python Recon Additions
□ pyproject.toml — [tool.mypy], [tool.ruff], [tool.pytest.ini_options]
□ setup.py / setup.cfg — legacy config
□ requirements.txt / requirements-dev.txt — dependency versions
□ conftest.py — pytest fixtures (critical for understanding test patterns)
□ __init__.py — package structure
□ Type stubs — are there py.typed markers? stub packages installed?Read pyproject.toml for type strictness
bash
cat pyproject.toml | grep -A 10 "\[tool.mypy\]"
cat pyproject.toml | grep -A 10 "\[tool.ruff\]"Python Verification Chain
bash
# Full chain — in this order
mypy . --strict # type correctness
ruff check . # lint (fast, Rust-based)
ruff format --check . # format check
pytest -v --tb=short # all tests
# With coverage
pytest --cov=src --cov-report=term-missing -v
# Type coverage
mypy . --strict 2>&1 | tail -5 # summary line shows error countPython-Specific Anti-Patterns
Never use bare except
python
BAD: except:
GOOD: except ValueError as e:
GOOD: except (TypeError, ValueError) as e:Never shadow builtins
python
BAD: list = [1, 2, 3] # shadows list()
BAD: id = user.id # shadows id()
GOOD: items = [1, 2, 3]
GOOD: user_id = user.idType annotations required (with mypy strict)
python
BAD: def process(data):
GOOD: def process(data: dict[str, Any]) -> ProcessResult:Use dataclasses or Pydantic over dicts for structured data
python
BAD: return {"user_id": 1, "name": "Alice"} # no type safety
GOOD: return UserResponse(user_id=1, name="Alice")Common Python Failure Modes
| Failure | Root Cause | Fix |
|---|---|---|
Optional[X] has no attribute Y | None not handled | Add if x is not None: guard |
Incompatible return value type | Wrong return type | Check function signature |
Missing return statement | Not all paths return | Add explicit return |
Module has no attribute X | Wrong import | Check module with dir(module) |
Cannot find implementation for X | Missing stub | Install types-X package |
| Circular import | Import at module level | Move to function level or restructure |
Test Patterns (pytest)
Fixture pattern
python
# conftest.py
import pytest
from myapp.db import get_db
@pytest.fixture
def db():
conn = get_db(":memory:")
yield conn
conn.close()
@pytest.fixture
def client(db):
from myapp import create_app
app = create_app({"TESTING": True})
with app.test_client() as c:
yield cStandard test structure
python
class TestUserAuth:
def test_login_success(self, client, db):
# Arrange
db.execute("INSERT INTO users VALUES (1, 'alice', 'hash')")
# Act
response = client.post("/login", json={"username": "alice", "password": "pw"})
# Assert
assert response.status_code == 200
assert response.json["token"] is not None
def test_login_wrong_password(self, client, db):
response = client.post("/login", json={"username": "alice", "password": "wrong"})
assert response.status_code == 401Parametrize for edge cases
python
@pytest.mark.parametrize("input,expected", [
("", ValueError),
(None, TypeError),
("valid@email.com", None),
("not-an-email", ValueError),
])
def test_validate_email(input, expected):
if expected:
with pytest.raises(expected):
validate_email(input)
else:
validate_email(input) # should not raiseFramework-Specific Notes
FastAPI
python
# Always test with TestClient, not raw function calls
from fastapi.testclient import TestClient
client = TestClient(app)
# Type all path/query params and bodies
@router.post("/users", response_model=UserResponse)
async def create_user(body: CreateUserRequest) -> UserResponse:
...Django
python
# Use pytest-django
# settings for tests
@pytest.mark.django_db
def test_user_creation():
user = User.objects.create_user(username="test", password="pass")
assert user.id is not NoneQuick Reference
bash
# Run single test file
pytest src/auth/test_session.py -v
# Run single test
pytest src/auth/test_session.py::TestSession::test_timeout -v
# Run with pdb on failure
pytest --pdb
# Show slowest tests
pytest --durations=10
# Type check single file
mypy src/auth/session.py --strict
