Python Development (3.14+)
Core Principles
- Stdlib first: External deps only when justified
- Type hints everywhere: All functions, all parameters
- Explicit over implicit: Clear is better than clever
- Fail fast: Raise early with informative errors
Toolchain
uv # Package management (not pip/poetry)
ruff # Lint + format (not flake8/black)
pytest # Testing
mypy # Type checking
Quick Patterns
Type Hints
def process_users(users: list[User], limit: int | None = None) -> list[Result]:
...
async def fetch_data(url: str, timeout: float = 30.0) -> dict[str, Any]:
...
Dataclasses
from dataclasses import dataclass, field
@dataclass
class Config:
host: str
port: int = 8080
tags: list[str] = field(default_factory=list)
Pattern Matching
match event:
case {"type": "click", "x": x, "y": y}:
handle_click(x, y)
case {"type": "key", "code": code}:
handle_key(code)
case _:
raise ValueError(f"Unknown event: {event}")
Python 3.14 Features
- Deferred annotations: No more
from __future__ import annotations - Template strings (t""):
t"Hello {name}" returns Template object - except without parens:
except ValueError, TypeError: - concurrent.interpreters: True parallelism via subinterpreters
- compression.zstd: Zstandard in stdlib
- Free-threaded build: No GIL (opt-in)
References
Tooling
uv sync # Install deps
ruff check --fix . # Lint and autofix
ruff format . # Format
pytest -v # Test
mypy . # Type check
