def test_fractions(self):
# Test sample variance with Fraction data.
data = [Fraction(1, 4), Fraction(1, 4), Fraction(3, 4), Fraction(7, 4)]
expected = 0.7071067811865476
assert statistics.stdev(data) == expected
assert Math.std(data) == expected
assert statistics.stdev(data) == Math.std(data)
def test_ints(self):
# Test sample variance with int data.
data = [4, 7, 13, 16]
exact = math.sqrt(30)
assert statistics.stdev(data) == exact
assert Math.std(data) == exact
assert statistics.stdev(data) == Math.std(data)
def test_decimals(self):
# Test sample variance with Decimal data.
data = [Decimal(2), Decimal(2), Decimal(7), Decimal(9)]
exact = (4 * Decimal('9.5') / Decimal(3)).sqrt()
assert statistics.stdev(data) == exact
assert Math.std(data) == exact
assert statistics.stdev(data) == Math.std(data)
assert isinstance(statistics.stdev(data), Decimal)