On Thu, Aug 3, 2017 at 9:55 AM, Serhiy Storchaka <storch...@gmail.com> wrote: > 03.08.17 18:36, Ian Kelly пише: >> >> The single variable is only a dict lookup if it's a global. Locals and >> closures are faster. >> >> def simple_cache(function): >> sentinel = object() >> cached = sentinel >> >> @functools.wraps(function) >> def wrapper(*args, **kwargs): >> nonlocal cached >> if args or kwargs: >> return function(*args, **kwargs) # No caching with args >> if cached is sentinel: >> cached = function() >> return cached >> return wrapper >> >> *Zero* dict lookups at call-time. If that's not (marginally) faster >> than lru_cache with maxsize=None I'll eat my socks. > > > With salt? > > $ ./python -m timeit -s 'from simple_cache import simple_cache; f = > simple_cache(int)' -- 'f()' > 500000 loops, best of 5: 885 nsec per loop > $ ./python -m timeit -s 'from functools import lru_cache; f = > lru_cache(maxsize=None)(int)' -- 'f()' > 1000000 loops, best of 5: 220 nsec per loop
Fixed: $ python3 -m timeit -s 'from simple_cache import simple_cache; f = simple_cache(int)' -- 'f()' 1000000 loops, best of 3: 0.167 usec per loop $ python3 -m timeit -s 'import sys; sys.modules["_functools"] = None; from functools import lru_cache; f = lru_cache(maxsize=None)(int)' -- 'f()' 1000000 loops, best of 3: 0.783 usec per loop -- https://mail.python.org/mailman/listinfo/python-list
