On Thu, 05 Oct 2006 00:02:51 +0200, Wildemar Wildenburger <[EMAIL PROTECTED]>
wrote:
> Jorgen Grahn wrote:
> Any use cases for these?
>> - the wildcard object, which compares equal to everything else
Like someone else wrote, for quick-and-dirty comparisons or lists and
dictionaries where I don't care about one part. I think I wanted it for
unittest's assertEqual(foo, bar) at one point.
self.assertEqual(['foo', 42, [], WILDCARD], my_result)
versus
self.assertEqual('foo', my_result[0])
self.assertEqual(42, my_result[1])
self.assertEqual([], my_result[2])
self.assertEqual(4, len(my_result))
# possibly assert that 'my_result' is a list-like
# object too
But I agree that the WILDCARD isn't the kind of object you want to spread
throughout your code; its behaviour is too odd.
>> - infinite xrange()s
Available in itertools, as someone pointed out.
>> - the black hole function 'def f(*args): pass'
I often find myself adding logging to functions by passing sys.stderr.write
as an argument to it. Passing blackhole is an elegant and fast way of
disabling logging.
>> - the identity function 'def f(x): return x'
I don't think I've used it. Maybe if you do a lot of manipulation of
functions and functors -- in some sense it's to function application what 0
is to addition, or 1 to multiplication.
/Jorgen
--
// Jorgen Grahn <grahn@ Ph'nglui mglw'nafh Cthulhu
\X/ snipabacken.dyndns.org> R'lyeh wgah'nagl fhtagn!
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