new_contents: class Solution(object):
      def hammingWeight(self, n):
          """
          :type n: int
          :rtype: int
          """
  		# ex:       00000000000000000000000000001011 (11)
  		# 						&
          #           00000000000000000000000000000001  (1)
          # will be   00000000000000000000000000000001
          # so numOnes will increment by 1.
          count = 0
          while n!=0:
  	        count += n&1
  	        n >>= 1 # shift n's bits to the right by 1.
          return count
          
  foo = Solution()
  print foo.hammingWeight(11)
  #Answer should be 3
subject: Add 191