lru_cache

Thread-safe LRU cache decorator with optional TTL expiration.

Installation

pip install lru_cache

Usage

from lru_cache import LruCache

@LruCache(maxsize=128, timeout=300)
def get_user(user_id: int) -> dict:
    # expensive operation
    return fetch_from_db(user_id)

# Invalidate a specific entry
get_user.invalidate(42)

# Clear all cached entries
get_user.cache_clear()

# Inspect cache state
get_user.cache_info()  # {'size': 10, 'maxsize': 128, 'timeout': 300}

Parameters

Parameter	Type	Default	Description
maxsize	int | None	None	Maximum number of cached entries. None = unbounded.
timeout	float | None	None	TTL in seconds. None = entries never expire.

Features

• Thread-safe: all operations protected by RLock
• TTL support: entries auto-expire after timeout seconds using monotonic clock
• LRU eviction: least-recently-used entries evicted when maxsize is reached
• Typed: full type annotations with py.typed marker (PEP 561)
• Zero dependencies: pure Python, no external packages

Migration from 0.x

The import path changed to fix a namespace collision (#4):

# Old (0.x)
from cache import LruCache

# New (1.x)
from lru_cache import LruCache

License

MIT