Pythonic way to iterate over bits of integer

Question

Let\'s a=109 or 1101101 in binary. How do I iterate over bits of this number, eg: [64, 32, 8, 4, 1]

Answer 1

The efficiency of F.J.'s answer can be dramatically improved.

from itertools import count,takewhile
[2**i for i in takewhile(lambda x:109>2**x,count()) if 109&2**i][::-1]

I like one liners :)

I did a quick timeit.Timer.timeit() against this and @Duncan. Duncan still wins but not the one liner is at least in the same class.

from timeit import Timer
duncan="""\
def bits(n):
 while n:
  b=n&(~n+1)
  yield b
  n^=b
"""
Duncan=Timer('list(bits(109))[::-1]',duncan)
Duncan.timeit()
4.3226630687713623
freegnu=Timer('[2**i for i in takewhile(lambda x:109>2**x,count()) if 109&2**i][::-1]','from itertools import count,takewhile')
freegnu.timeit()
5.2898638248443604