With Basic Error Handling Range Check

BinarySearch.py

def binarySearch(list, item):
    first = 0
    last = len(list) - 1

    if item < list[first] or item > list[last]:
        return (item,-1)
    
    while first <= last:
        i = (first + last) // 2
    
        if list[i] == item:
            return (item,i)
        elif list[i] > item:
            last = i - 1
        elif list[i] < item:
            first = i + 1
        else:
            return (item,-1)

def main():
    ls = [x*10 for x in range(1,11)]
    print(ls)
    (element,index) = binarySearch(ls, -10)
    print("index : %s element: %s" %(index, element))


if __name__ == "__main__":
    main()