test_decimal.py 文件源码

def test_explicit_context_create_from_float(self):

        Decimal = self.decimal.Decimal

        nc = self.decimal.Context()
        r = nc.create_decimal(0.1)
        self.assertEqual(type(r), Decimal)
        self.assertEqual(str(r), '0.1000000000000000055511151231')
        self.assertTrue(nc.create_decimal(float('nan')).is_qnan())
        self.assertTrue(nc.create_decimal(float('inf')).is_infinite())
        self.assertTrue(nc.create_decimal(float('-inf')).is_infinite())
        self.assertEqual(str(nc.create_decimal(float('nan'))),
                         str(nc.create_decimal('NaN')))
        self.assertEqual(str(nc.create_decimal(float('inf'))),
                         str(nc.create_decimal('Infinity')))
        self.assertEqual(str(nc.create_decimal(float('-inf'))),
                         str(nc.create_decimal('-Infinity')))
        self.assertEqual(str(nc.create_decimal(float('-0.0'))),
                         str(nc.create_decimal('-0')))
        nc.prec = 100
        for i in range(200):
            x = random.expovariate(0.01) * (random.random() * 2.0 - 1.0)
            self.assertEqual(x, float(nc.create_decimal(x))) # roundtrip