@lru_cache on functions with no arguments

[Serhiy Storchaka]

03.08.17 19:08, Ian Kelly пише:
> This turns out to be because I was running 3.4 which doesn't have the
> C implementation to begin with. In 3.6 this trick doesn't seem to work
> as expected for disabling it:

It didn't work because the functools module already was imported at startup.

$ ./python -m timeit -s 'from simple_cache import simple_cache; f = 
simple_cache(int)' -- 'f()'
500000 loops, best of 5: 501 nsec per loop

$ ./python -m timeit -s 'from functools import lru_cache; f = 
lru_cache(maxsize=None)(int)' -- 'f()'
2000000 loops, best of 5: 139 nsec per loop

$ ./python -m timeit -s 'import sys; sys.modules["_functools"] = None; 
del sys.modules["functools"]; from functools import lru_cache; f = 
lru_cache(maxsize=None)(int)' -- 'f()'
100000 loops, best of 5: 3.39 usec per loop