Python Functions
Args, kwargs, lambdas, and signatures that document themselves.
- python functions
- args kwargs
- lambda
- lru_cache
- type hints
Python Functions
Args, kwargs, lambdas, and signatures that document themselves.
Commands
| Command | What it does |
|---|---|
def f(name, *, verbose=False): | Keyword-only arg after * |
def f(*args, **kwargs): | Catch-all parameters |
lambda x: x * 2 | Tiny anonymous function |
functools.lru_cache | Memoize pure functions |
def f(path: str) -> int: | Type-annotated signature |
Example
from functools import lru_cache
@lru_cache(maxsize=1024)
def fib(n: int) -> int:
return n if n < 2 else fib(n-1) + fib(n-2)FAQ
**When is *args/kwargs right?
Decorators and pass-through wrappers; concrete signatures are better for public APIs.
Do type hints run at runtime?
No — they are metadata for mypy/IDEs; use pydantic or asserts for runtime validation.
常見問題
When is *args/**kwargs right?
Decorators and pass-through wrappers; concrete signatures are better for public APIs.
Do type hints run at runtime?
No — they are metadata for mypy/IDEs; use pydantic or asserts for runtime validation.
Python
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Syntax survival kit: variables, loops, f-strings, and errors.
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