def test_when_population_size_is_lower_than_selection_size(self):
""" Cannot select more individuals than population size. """
p_size = 10
population = utils.DummyPopulation(size=p_size)
with self.assertRaises(PyneticsError):
Tournament(sample_size=int(p_size / 2))(population, p_size * 2)
def test_when_population_size_is_equals_to_selection_size(self):
""" All the population is returned. """
p_size = 10
individuals = utils.individuals(p_size)
population = utils.DummyPopulation(size=p_size,
individuals=individuals)
selected_individuals = BestIndividual()(population, p_size)
self.assertEquals(len(selected_individuals), len(population))
def test_when_population_size_is_bigger_than_selection_size(self):
""" The best individuals are returned. """
p_size = 10
selection_size = int(p_size / 2)
population = utils.DummyPopulation(size=p_size)
individuals = BestIndividual()(population, selection_size)
self.assertEquals(len(individuals), selection_size)
for i in range(len(individuals)):
self.assertEquals(individuals[i], population[i])
def test_individuals_are_correctly_added_to_the_population(self):
size = 10
individuals = utils.individuals(size + 1)
population = utils.DummyPopulation(size=size,
individuals=individuals[:10])
self.assertEquals(size, len(population))
population.append(individuals[10])
self.assertEquals(size + 1, len(population))
self.assertIn(individuals[10], population)
def test_population_maintain_size_at_initialization_time(self):
""" Size is kept when initializing.
That means that, if a population is initializated with size n, it will
have n individuals, regardless the number of individuals are passed as
parameter.
"""
size = 10
individuals_list = [[], utils.individuals(10), utils.individuals(100)]
for individuals in individuals_list:
self.assertEquals(
size,
len(utils.DummyPopulation(size=size, individuals=individuals)))
def test_best_individuals_are_returned(self):
size = 10
individuals = utils.individuals(size)
population = utils.DummyPopulation(size=size, individuals=individuals)
self.assertEquals(population.best().fitness(),
individuals[-1].fitness())
def test_population_shrinks_when_individual_is_removed(self):
size = 10
population = utils.DummyPopulation(size=size)
for i in range(10):
self.assertEquals(size - i, len(population))
del population[0]
def test_population_length_is_computed_correctly(self):
sizes = (1, 10, 100, 1000)
for size in sizes:
self.assertEquals(size, len(utils.DummyPopulation(size=size)))
def test_cannot_initialize_a_population_of_size_0_or_less(self):
for size in (-100, -10, -1, 0):
with self.assertRaises(InvalidSize):
utils.DummyPopulation(size=size)
def test_class_is_pickeable(self):
""" Checks is pickeable by writing it into a temporary file. """
with TemporaryFile() as f:
pickle.dump(utils.DummyPopulation(size=10), f)
def test_error_if_more_selections_than_size_when_not_repetition(self):
""" When no repetable and requested more individuals than available. """
population = utils.DummyPopulation(10)
for i in range(1, 10):
with self.assertRaises(PyneticsError):
utils.DummySelection()(population, len(population) + 1)