leetcode Search for a Range python

class Solution(object):
    def searchRange(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """

        left=0
        right=len(nums)-1

        while left <= right:
            mid=(left+right)/2
            if nums[mid] > target:
                right=mid-1
            elif nums[mid] < target:
                left=mid+1
            else:
                rs=[0,0]
                if nums[left] == target:
                    rs[0] = left
                if nums[right] == target:
                    rs[1] = right
                for i in range(mid,right+1):
                    if nums[i] != target:
                        rs[1] = i-1
                        break
                for i in range(mid,left-1,-1):
                    if nums[i] != target:
                        rs[0] = i + 1
                        break
                return rs
        return [-1,-1]