Binary search in Python (binary search)

This is Qiita's first post.

This time, I implemented binary search in two patterns, loop and recursion.

Binary search in loop

`binary_search_loop.py`


from typing import List


def binary_search_loop(data: List[int], target: int) -> int:
    left, right = 0, len(data)

    while left <= right:
        mid = (left + right) // 2
        if data[mid] == target:
            return mid
        elif data[mid] < target:
            left = mid + 1
        else:
            right = mid - 1

    return None


if __name__ == "__main__":
    data: List[int] = [int(x) for x in input("Sorted array(Space delimited)Enter: ").split()] #I used the inclusion notation
    target = int(input("Enter target: "))

    result = binary_search_loop(data, target)
    if result is not None:
        print(f"found: {result}Was second")
    else:
        print("not found")

Recursive binary search

`binary_search_recursion.py`


from typing import List


def binary_search_recursion(data: List[int], target: int) -> int:
    def recursion(left=0, right=len(data) - 1):
        if left > right:
            return None

        mid = (left + right) // 2
        if data[mid] == target:
            return mid
        elif data[mid] < target:
            return recursion(mid + 1, right)
        else:
            return recursion(left, mid - 1)

    return recursion()


if __name__ == "__main__":
    data: List[int] = list(map(int, input("Sorted array(Space delimited)Enter: ").split())) #Using map
    target = int(input("Enter target: "))

    result = binary_search_recursion(data, target)
    if result is not None:
        print(f"found: {result}Was second")
    else:
        print("not found")

What I noticed

--Since the data obtained by input () is str type, convert it to int type. --If it is still str type, it will be compared by character code instead of number in comparison.