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.. _propcache-api:
=========
Reference
=========
.. module:: propcache.api
cached_property
===============
.. decorator:: cached_property(func)
This decorator functions exactly the same as the standard library
:func:`cached_property` decorator, but it's available in the
:mod:`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
=====================
.. decorator:: 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
:func:`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
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