numpy

u = numpy.array([4.0, 4.0])

v = numpy.array([4.0, 0])

(u.dot(v)/u.dot(u))*u

(u.dot(v)/v.dot(v))*v

import numpy
from numpy import array, inner, dot, multiply, sum
from math import acos, sqrt

u = array([1, 0], dtype='float')

v = array([0, 1], dtype='float')

u.dot(v)

u.dot(u)

4 * u

3 * u + 4 * v

u * 4 == 4 * u

-(u + v).dot(u)

u * v

numpy.sum(u+v)