Python ：二进制中1的个数

牛客网上的剑指 offer的在线编程：

题目描述:

# -*- coding:utf-8 -*-class Solution:    def NumberOf1(self, n):        if n >= 0:            bina = bin(n)            count = bina.count('1')            return count        else:            bina = bin(abs(n) - 1)            count = 32 - bina.count('1')            return count