To be clear, my original post had a goof.
So my original, de-goofed, idiom was
class Foo (object) :
_lazy = None
def foo(self, x) :
self._lazy = self._lazy or self.get_something(x)
def get_something(self, x) :
# doesn't really matter, so long as it returns truthy result
and the new, improved idiom is
class Foo (object) :
def foo(self, x) :
self._lazy = getattr(self, "_lazy", None) or self._get_something(x)
def _get_something(self, x) :
# doesn't really matter, so long as it returns truthy result
I was laboring under some misconception that there was Python magic that
allowed __init__ and only __init__ to add class attributes by setting their
values. Good to know this piece of magic isn't part of Python, and thus lazy
eval can be handled more cleanly than I originally thought.
In other words, "Guido was here".
Thanks again
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