test_decimal.py 文件源码

def test_explicit_from_float(self):
        r = Decimal(0.1)
        self.assertEqual(type(r), Decimal)
        self.assertEqual(str(r),
                '0.1000000000000000055511151231257827021181583404541015625')
        self.assertTrue(Decimal(float('nan')).is_qnan())
        self.assertTrue(Decimal(float('inf')).is_infinite())
        self.assertTrue(Decimal(float('-inf')).is_infinite())
        self.assertEqual(str(Decimal(float('nan'))),
                         str(Decimal('NaN')))
        self.assertEqual(str(Decimal(float('inf'))),
                         str(Decimal('Infinity')))
        self.assertEqual(str(Decimal(float('-inf'))),
                         str(Decimal('-Infinity')))
        self.assertEqual(str(Decimal(float('-0.0'))),
                         str(Decimal('-0')))
        for i in range(200):
            x = random.expovariate(0.01) * (random.random() * 2.0 - 1.0)
            self.assertEqual(x, float(Decimal(x))) # roundtrip