If we use Python as programming language and wish to venture beyond scikit-learn, tensorflow and similar software which makes our lives so much easier, we need to dive into the wonderful world of quadratic programming. We can, if we wish, solve the minimization problem using say standard gradient methods or conjugate gradient methods. However, these methods tend to exhibit a rather slow converge. So, welcome to the promised land of quadratic programming.
The functions we need are contained in the quadratic programming package CVXOPT and we need to import it together with numpy as
import numpy
import cvxopt
This will make our life much easier. You don't need t write your own optimizer.