def testvariance_returns_populationVariance(self):
popList = [1, 2, 3, 4, 5]
stat = Statistics(popList)
actual = stat.variance()
expected = 2
self.assertEqual(actual, expected)
def testvariance_return_sampleVariance(self):
list = [1, 2, 3, 4, 5]
stat = Statistics(list)
actual = stat.variance(population=False)
expected = 2.5
self.assertEqual(expected, actual)
def testvariance_returns_none(self):
emptyList = []
stat = Statistics(emptyList)
actual = stat.variance()
expected = None
self.assertEqual(expected, actual)
