thebjorn <[EMAIL PROTECTED]> wrote:
> It would have been nice to be able to write
>
> class Foo(object):
> @property
> def expensive(self):
> self.expensive = <insert expensive db call here>
> return self.expensive
>
> but apparently I "can't set [that] attribute" :-(
You can set and access it directly in __dict__. How about something along
these lines:
def cachedproperty(f):
name = f.__name__
def getter(self):
try:
return self.__dict__[name]
except KeyError:
res = self.__dict__[name] = f(self)
return res
return property(getter)
class Foo(object):
@cachedproperty
def expensive(self):
print "expensive called"
return 42
>>> f = Foo()
>>> f.expensive
expensive called
42
>>> f.expensive
42
It is still calling the getter every time though, so not as fast as a plain
attribute lookup.
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