计算数字在二进制下有多少个1

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计算数字在二进制下有多少个1

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代码

def count_yi(num):
	if num == 0:
	    return 0
	else:
	    return count_yi(num & num - 1) + 1
if __name__ == '__main__':
	print(count_yi(127))

最后结果为：7