import numpy

genes = 2
chromosomes = 10
mattingPoolSize = 6
offspringSize = chromosomes - mattingPoolSize
lb = -5
ub = 5
populationSize = (chromosomes, genes)
generations = 3

population = numpy.random.uniform(lb, ub, populationSize)

for generation in range(generations):
    print(("Generation:", generation+1))
    fitness = numpy.sum(population*population, axis=1)
    print("\npopulation")
    print(population)
    print("\nfitness calculation")
    print(fitness)
    
    parents = numpy.empty((mattingPoolSize, population.shape[1]))
    
    for p in range(mattingPoolSize):
        fittestIndex = numpy.where(fitness == numpy.max(fitness))
        fittestIndex = fittestIndex[0][0]
        parents[p, :] = population[fittestIndex, :]
        fitness[fittestIndex] = -1
    print("\nparents:")
    print(parents)
    
    offspring = numpy.empty((offspringSize, population.shape[1]))
    
    for k in range(offspringSize):
        crossoverpoint = numpy.random.randint(0, genes)
        parent1Index = k%parents.shape[0]
        parent2Index = (k+1)%parents.shape[0]
        offspring[k, 0: crossoverpoint] = parents[parent1Index, 0: crossoverpoint]
        offspring[k, crossoverpoint:] = parents[parent2Index, crossoverpoint:]
    print("\nOffspring after crossover")
    print(offspring)
    
    for index in range(offspring.shape[0]):
        
        randomIndex = numpy.random.randint(1,genes)
        randomvalue = numpy.random.uniform(lb,ub,1)
        offspring[index,randomIndex]=offspring[index,randomIndex]+randomvalue
    print("\nOffspring after mutation")
    print(offspring)
    
    population[0:parents.shape[0], :] = parents
    population[parents.shape[0]:, :] = offspring
    print("\nNew population for next generation:")
    print(population)
    
fitness = numpy.sum(population*population, axis=1)
fittestIndex = numpy.where(fitness == numpy.max(fitness))

fittestIndex = fittestIndex[0][0]
fittestInd = population[fittestIndex, :]
bestFitness = fitness[fittestIndex]
print("\nbest individual:")
print(fittestInd)
print("\nBest Individual's Fitness:")
print(bestFitness)