`functools.cache` is available only from Python3.9

[GokulNC]

The recent release 2.1 does not seem to work with any python version < 3.9

AttributeError: module 'functools' has no attribute 'cache'

Solution: https://stackoverflow.com/a/70301476/

[virtualvinodh]

I suppose I can just replace cache with lru_cache?

V

[virtualvinodh]

Fixed.