Reference

cached_property

@propcache.api.cached_property(func)

This decorator functions exactly the same as the standard library cached_property() decorator, but it’s available in the propcache.api module along with an accelerated Cython version.

As with the standard library version, the cached value is stored in the instance’s __dict__ dictionary. To clear a cached value, you can use the del operator on the instance’s attribute or call instance.__dict__.pop('attribute_name', None).

under_cached_property

@propcache.api.under_cached_property(func)

Transform a method of a class into a property whose value is computed only once and then cached as a private attribute. Similar to the cached_property() decorator, but the cached value is stored in the instance’s _cache dictionary instead of __dict__.

Example:

from propcache.api import under_cached_property

class MyClass:

    def __init__(self, data: List[float]):
        self._data = data
        self._cache = {}

    @cached_property
    def calculated_data(self):
        return expensive_operation(self._data)

    def clear_cache(self):
        self._cache.clear()

instance = MyClass([1.0, 2.0, 3.0])
print(instance.calculated_data)  # expensive operation

instance.clear_cache()
print(instance.calculated_data)  # expensive operation