lru_cache issue

when using the lru_cache from the functools module, many like to set maxsize=None. However, when decorating a method with lru_cache, the caches wouldn't get destroyed when the object is deleted by the garbage collector. This would create the problem that the cache would keep growing and growing.

The reason behind this is the decorator makes the method a callable class attribute. Therefore it will only get deleted when the class is deleted, not the object. To avoid this, one can create a private method, and create a callable instance attribute when initializing by the following code:

self.method_name = functools.lru_cache(maxsize=None)(self._method_name)

Reference

• https://www.youtube.com/watch?v=sVjtp6tGo0g&ab_channel=anthonywritescode