Double matrix method for calculating Fibonacci

fibonacci.py

def matrix_fibonacci(target: int) -> int:
    """
    This is the fastest way to compute a fibonacci number, using matrix mathematics.
    It completes quickly.
    The math is explained in detailed on the Wiki page at: https://en.wikipedia.org/wiki/Fibonacci_number#Matrix_form


    >>> matrix_fibonacci(80)
    23416728348467685

    """
    v1, v2, v3 = (
        1,
        1,
        0,
    )  # initialise a matrix [[1,1],[1,0]] of the first two numbers in the sequence

    for record in bin(
            target
    )[3:]:  # perform fast exponentiation of the matrix (quickly raise it to the nth power)
        calc = v2 * v2
        v1, v2 = v1 * v1 + calc, (v1 + v3) * v2
        v3 = calc + v3 * v3

        if record is "1":
            v1, v2, v3 = v1 + v2, v1, v2
    return int(v2)