varOr + numpy multinomial

gistfile1.py

def varOr(toolbox, population, lambda_, cxpb, mutpb):
    assert (cxpb + mutpb) <= 1.0, ("The sum of the crossover and mutation "
        "probabilities must be smaller or equal to 1.0.")
    
    ncx, nmut, nrep = numpy.random.multinomial(lambda_, (cxpb, mutpb, 1-cxpb-mutpb))
    offcx = map(toolbox.clone, tools.selRandom(population, 2*ncx))
    offmut = map(toolbox.clone, tools.selRandom(population, nmut))
    offrep = map(toolbox.clone, tools.selRandom(population, nrep))

    for ind1, ind2 in offcx:
        toolbox.mate(ind1, ind2)
        del ind1.fitness.values, ind2.fitness.values
    offcx = offcx[::2]

    for ind in offmut:
        toolbox.mutate(ind)
        del ind.fitness.values
    
    return random.shuffle(offcx + offmut + offrep)