Closest In Sorted Array in Python(Binary Search)

Given a target integer T and an integer array A sorted in ascending order, find the index i in A such that A[i] is closest to T.

Assumptions:

There can be duplicate elements in the array, and we can return any of the indices with same value.

Examples:

A = {1, 2, 3}, T = 2, return 1
A = {1, 4, 6}, T = 3, return 1
A = {1, 4, 6}, T = 5, return 1 or 2
A = {1, 3, 3, 4}, T = 2, return 0 or 1 or 2

def find_closest_num(nums,target):
  if len(nums) == 0:
    return -1
  left = 0
  right = len(nums) - 1
  while left < right - 1:
    mid = (left + right)/2
    if nums[mid] > target:
      right = mid
    elif nums[mid] < target:
      left = mid
    else:
      return mid
  return left if abs(nums[left] - target) < abs(nums[right] - target) else right