En Tue, 10 Mar 2009 13:00:18 -0200, Vito De Tullio
<zak.mc.kra...@libero.it> escribió:
MRAB wrote:
>>> (lambda arg: arg) == (lambda arg: arg)
False
curious...
I somehow thinked that, whereas
(lambda: 0) is (lambda: 0)
should be False (obviously)
(lambda: 0) == (lambda: 0)
could be True... maybe because `{} == {} and {} is not {}` (also for [])
Neither {} nor [] have any attributes by their own; people is only
interested in their contents. Even a bare object() (that has no
attributes) compare unequal to another instance:
py> object() == object()
False
But functions (and lambda is just syntactic sugar for an anonymous
function) have many attributes:
__dict__, func_dict
__doc__, func_doc
__module__
__name__, func_name
func_closure
func_code
func_defaults
func_globals
'==' should compare all of them, and hash() should take them into account
too... Too much effort just for the very few cases when two functions
actually would compare "equal" - and, who cares?
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
