fibonacci.py

### Fibonacci function (wrapper and helper) without loops, recusive, in O(n) complexity

def fibonacci(n):
    if n < 0:
        raise Exception("negative input", n)
    else:
        return fibonacci_helper(n, 0, 0, 0)

def fibonacci_helper(n, index, term_1, term_2):
    if index == n:
        return term_1
    elif index == 0:
        return fibonacci_helper(n, index + 1, 1, 0)
    else:
        return fibonacci_helper(n, index + 1, term_1 + term_2, term_1)

print(fibonacci(50))

merge.py

### Merge function

def merge(original, add, delete):
    # copying original so it's not edited
    result = []
    for item in original:
        result.append(item)
    # adding
    for item in add:
        result.append(item)
    # removing duplicates
    result = list(dict.fromkeys(result))
    # removing
    for item in delete:
        result.remove(item)
    # sort by length, and by alphabetical
    for i in range(len(result)):
        result[i] = [len(result[i]), result[i]]
    result.sort(key = lambda x: (x[0], x[1]), reverse = True)
    # cleanup
    for i in range(len(result)):
        result[i] = result[i][1]
    return result

print(merge(['one', 'two', 'three'], ['one', 'two', 'five', 'six'], ['two', 'five']))