Python实现二分查找

话不多说，直接上代码：

def search(sequence,number,lower=0,upper=None):
	if upper is None: upper = len(sequence) - 1
	if lower== upper:
		assert number == sequence[upper]
		return upper
	else:
		middle = (lower + upper) //2
		if number > sequence[middle]:
			return serch(sequence,number,middle + 1,upper)
		else:
			return serch(sequence,number,lower,middle)