Identical descriptor value, without leaking memory?
Ian Kelly
ian.g.kelly at gmail.com
Fri Jul 29 19:03:15 EDT 2011
On Fri, Jul 29, 2011 at 5:01 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Mon, Jul 25, 2011 at 11:46 AM, Jack Bates <ms419 at freezone.co.uk> wrote:
>> How can you get a descriptor to return an identical value, each time
>> it's called with the same "instance" - without leaking memory?
Oops, that should have been:
class MyDescriptor(object):
def __get__(self, instance, owner):
try:
return instance.__cached_value[self]
except AttributeError:
instance.__cached_value = {self: get_value(instance, owner)}
except KeyError:
instance.__cached_value[self] = get_value(instance, owner)
return instance.__cached_value[self]
class MyClass(object):
my_attribute = MyDescriptor()
More information about the Python-list
mailing list