An example of machine learning from https://youtu.be/wUPFOFbCeFI

Learn a line .py

from random import random
from math import pow

ys_and_xs = [ (1, 3.8), (2, 1.9), (3, 2.9), 
              (4, 4.5), (5, 6.4), (6, 3.5), 
              (7, 6.7), (8, 6.2), (9, 8.0) ]


def grade(a, b):
    error = 0
    for x,y in ys_and_xs:
        error += pow( a*x + b - y , 2 )
    return error



def someChange():
    return random() - .5


a = 1
b = 0
err = grade(a,b)

for _ in range(100000):
    new_a = a + someChange()
    new_b = b + someChange()
    new_err = grade(new_a, new_b)
    if new_err < err:
        a = new_a
        b = new_b
        err = new_err
        print "a =", a, ", b =", b