Re: [Numpy-discussion] Changing FFT cache to a bounded LRU cache

You can backport the pure Python version of lru_cache for Python 2 (or vendor the backport done here: https://pypi.python.org/pypi/backports.functools_lru_cache/). The advantage is that lru_cache is C-accelerated in Python 3.5 and upwards...

That's a pretty big back-port. The speed also does not matter for this particular use-case: Time for the actual FFT will dominate by far. The lru_cache decorator can furthermore only limit the cache size by item count and not size in memory as the proposed solution does. I think the downsides outweigh the advantages of being able to use functionality from the stdlib.