211117-1127 python simple TTL time-based caching
lru_cache, really easy to add it as decorator to a function to cache the responses! Example directly copied from caching - Python in-memory cache with time to live - Stack Overflow:
from functools import lru_cache import time @lru_cache() def my_expensive_function(a, b, ttl_hash=None): del ttl_hash # to emphasize we don't use it and to shut pylint up return a + b # horrible CPU load... def get_ttl_hash(seconds=3600): """Return the same value withing `seconds` time period""" return round(time.time() / seconds) # somewhere in your code... res = my_expensive_function(2, 2, ttl_hash=get_ttl_hash()) # cache will be updated once in an hour
Used it practically in some code that called an expensive external function multiple times. Bad code I didn’t have time to fix, but it took 2.5 seconds to run. Adding the lines above shortened the runtime from ~2.5 seconds to 0.02 seconds with cache lifetime of 60 seconds.
Didn’t update the function at all without the
del ttl_hash and default none parameter bit, TODO understand what’s really happening there.