On Fri, 04 Feb 2005 16:44:48 -0500, Daniel Bickett wrote:
> [ False , False , True , None ]
>
> False would be returned upon inspection of the first index, even
> though True was in fact in the list. The same is true of the code of
> Jeremy Bowers, Steve Juranich, and Jeff Shannon. As for Raymond
> Hettinger, I can't even be sure ;)
Nope. To recall, my code was:
seenFalse = False
for item in list:
if item: return True
if item is False: seenFalse = True
if seenFalse:
return False
return None
So, turning that into a real function and not a sketch:
Python 2.3.4 (#1, Jan 25 2005, 21:29:33)
[GCC 3.4.3 (Gentoo Linux 3.4.3, ssp-3.4.3-0, pie-8.7.6.6)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> def thingy(l):
... seenFalse = False
... for item in l:
... if item: return True
... if item is False: seenFalse = True
... if seenFalse:
... return False
... return None
...
>>> thingy([ False , False , True , None ])
True
>>>
The defense rests, your honor. :-)
(I like the later use of "returnValue" and the reduce solution was cute
and quite educational (very appropriate here). I deliberately eschewed
fanciness, though.)
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