How do I get the info for a cached property?

How do I get the info for a cached property? - Printable Version

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How do I get the info for a cached property? - arnavb - Sep-01-2018

Say I have the following class with a property that has an expensive operation:

from functools import lru_cache

class Example:
    @property
    @lru_cache(maxsize=None)
    def a_getter(self):
        print('Doing an expensive operation!')
        expensive_result = 5
        return expensive_result

test = Example()

for i in range(0, 1000):
    a_variable = test.a_getter

print(test.a_getter.cache_info())

As evident, this does not run with 3.6.1, with the traceback:

Error:Traceback (most recent call last):
  File "python", line 16, in <module>
AttributeError: 'int' object has no attribute 'cache_info'

However, if I remove the property decorator, then the code works (I just have to switch to a function call for the getter).

Is there a way for me to get this cache info with the property decorator as well?

RE: How do I get the info for a cached property? - buran - Sep-02-2018

Maybe not the best, but

from functools import lru_cache
 
class Example:

    @property
    def a_getter(self):
        return self._a_getter()

    @lru_cache(maxsize=None)
    def _a_getter(self):
        print('Doing an expensive operation!')
        expensive_result = 5
        return expensive_result
 
test = Example()
 
for i in range(0, 1000):
    a_variable = test.a_getter
 
print(test._a_getter.cache_info())

would be interesting to see other suggestions

RE: How do I get the info for a cached property? - Gribouillis - Sep-02-2018

Use

print(Example.a_getter.fget.cache_info())

RE: How do I get the info for a cached property? - arnavb - Sep-02-2018

Thanks guys! Both of your solutions worked, but @Gribouillis's solution fits my needs better. Big Grin

(Also unrelated question, but does this site have a method of marking threads solved or anything, by any chance?)