[Python]二分查找算法实现

二分查找算法程序如下：

class Solution:
def binarysearch(self, nums, target):
"""
:type nums:list
:type target: int
:rtype:int
"""
left = 0
right = len(nums)-1
while left <= right:
middle = (left+right)//2
if nums[middle]==target:
return middle
elif nums[middle] < target:
left = middle + 1
else:
right = middle - 1

return -1