Implementing Binary Search in Python

def binary_search(arr, elem):
    start, end = 0, len(arr)-1

    while start <= end:
        mid = (start+end)//2

        if elem == arr[mid]:
            return mid
        elif elem < arr[mid]:
            end = mid-1
        else:
            start = mid+1

    else:
        return False

arr, choice = [], "y"
print("The List is now Empty...\nPlease Enter some elements into it...\n")

while choice.lower() == "y":
    elem = int(input("Enter the INTEGER element to be inserted : "))
    arr.append(elem)
    print("\nNow the List contains : ", arr)

    choice = input("\nDo You Want to insert more elements into it? (Y/[n]) : ")

find = int(input("Enter the Element to be found : "))
pos = binary_search(arr, find)

if bool(pos):
    print(f"The element is found at {pos+1} position")
else:
    raise ValueError("Oops!!! The Given Element is NOT PRESENT in the given list")