How to use the vector.V function in vector

def rect_from_line(line):
    """ Creates a rectangle from a line primitive by thickening it 
        according to the primitive's aperture size.

        Treats rectangular apertures as square because otherwise the maths
        becomes too hard for my brain.
    """
    r = get_aperture_size(line.aperture) / 2.0

    start_v = V.from_tuple(line.start)
    end_v = V.from_tuple(line.end)

    dir_v = end_v - start_v
    # normalize direction vector
    abs_dir_v = abs(dir_v)
    if abs_dir_v:
        dir_v = dir_v / abs_dir_v
    else:
        dir_v = V(0, 0)

    # 45 degree angle means the vector pointing to the new rectangle edges has to be sqrt(2)*r long
    v_len = math.sqrt(2)*r

    # Give the direction vector the appropriate length
    dir_v *= v_len

    v1 = (start_v + dir_v.rotate(135, as_degrees=True)).as_tuple()

def rotate(self, theta, as_degrees=False):
        """ Adapted from https://gist.github.com/mcleonard/5351452.
            Rotate this vector by theta in degrees.
        """
        if as_degrees:
            theta = math.radians(theta)

        dc, ds = math.cos(theta), math.sin(theta)
        x, y = dc*self.x - ds*self.y, ds*self.x + dc*self.y
        return V(x, y)

def consume_tuple(self, other):
        if isinstance(other, tuple) or isinstance(other, list):
            return V(other[0], other[1])
        return other

Treats rectangular apertures as square because otherwise the maths
        becomes too hard for my brain.
    """
    r = get_aperture_size(line.aperture) / 2.0

    start_v = V.from_tuple(line.start)
    end_v = V.from_tuple(line.end)

    dir_v = end_v - start_v
    # normalize direction vector
    abs_dir_v = abs(dir_v)
    if abs_dir_v:
        dir_v = dir_v / abs_dir_v
    else:
        dir_v = V(0, 0)

    # 45 degree angle means the vector pointing to the new rectangle edges has to be sqrt(2)*r long
    v_len = math.sqrt(2)*r

    # Give the direction vector the appropriate length
    dir_v *= v_len

    v1 = (start_v + dir_v.rotate(135, as_degrees=True)).as_tuple()
    v2 = (start_v + dir_v.rotate(-135, as_degrees=True)).as_tuple()
    v3 = (end_v + dir_v.rotate(-45, as_degrees=True)).as_tuple()
    v4 = (end_v + dir_v.rotate(45, as_degrees=True)).as_tuple()

    return [v1, v2, v3, v4]

def from_tuple(cls, coordinates):
        x, y = coordinates
        return V(x, y)

def __mul__(self, other):
        other = self.consume_tuple(other)
        if isinstance(other, V):
            return (self.x * other.x + self.y * other.y)
        return V(other * self.x, other * self.y)

def __add__(self, other):
        other = self.consume_tuple(other)
        return V(self.x + other.x, self.y + other.y)

def __mul__(self, other):
        other = self.consume_tuple(other)
        if isinstance(other, V):
            return (self.x * other.x + self.y * other.y)
        return V(other * self.x, other * self.y)