Binary Search

class Solution:
    def search(self, nums: List[int], target: int) -> int:

        # Initialise our bounds to start and end of nums array
        left_index = 0
        right_index = len(nums) - 1

        # Loop while we have not yet searched all numbers
        while left_index <= right_index:

            # Search the middle number of our range
            mid_index = (left_index + right_index) // 2
            mid_num = nums[mid_index]

            # If target found, return mid_index
            if mid_num == target:
                return mid_index

            # If target is greater than mid number
            if mid_num < target:
                left_index = mid_index + 1

            # If target is less than mid number
            else:
                right_index = mid_index - 1

        # If target not found, return -1
        return -1