python2.4 generator expression > python2.3 list expression

[Bryan]

Christos TZOTZIOY Georgiou wrote:
> On 21 Feb 2005 06:48:19 -0500, rumours say that Dan Sommers <me at privacy.net>
> might have written:
> 
> [snip: snacktime posts code to count bits]
> 
> 
>>>Seems to work, is there a better way to do this?
> 
> 
> [Dan]
> 
>>for c in range( 128 ):
>>   even_odd = 0
>>   print '%3d' % c,
>>   while c:
>>       c &= c - 1
>>       even_odd = not even_odd
>>   print int( even_odd )
> 
> 
> Just for the sake of people who haven't messed with bit manipulation in C or
> assembly, the effect of
> 
> c &= c - 1
> 
> is to reset the rightmost (less significant) '1' bit of a number (ie change it
> to '0').

i tried c &= c - 1 but i'm not getting the least significant or rightmost bit 
reset to zero.  am i misunderstanding something?

 >>> 2 & 1  # 2 = 0x10; reset right most would be 0x10
0
 >>> 10 & 9 # 10 = 0x1010; reset right most would be 0x1010
8

bryan