Method testInitFromIntegerRatio

Lib/test/test_fractions.py:364–394

(self)

        self.assertRaises(OverflowError, F, Decimal('-inf'))

    def testInitFromIntegerRatio(self):
        self.assertEqual((7, 3), _components(F(Ratio((7, 3)))))
        errmsg = (r"argument should be a string or a Rational instance or "
                  r"have the as_integer_ratio\(\) method")
        # the type also has an "as_integer_ratio" attribute.
        self.assertRaisesRegex(TypeError, errmsg, F, Ratio)
        # bad ratio
        self.assertRaises(TypeError, F, Ratio(7))
        self.assertRaises(ValueError, F, Ratio((7,)))
        self.assertRaises(ValueError, F, Ratio((7, 3, 1)))
        # only single-argument form
        self.assertRaises(TypeError, F, Ratio((3, 7)), 11)
        self.assertRaises(TypeError, F, 2, Ratio((-10, 9)))

        # as_integer_ratio not defined in a class
        class A:
            pass
        a = A()
        a.as_integer_ratio = lambda: (9, 5)
        self.assertEqual((9, 5), _components(F(a)))

        # as_integer_ratio defined in a metaclass
        class M(type):
            def as_integer_ratio(self):
                return (11, 9)
        class B(metaclass=M):
            pass
        self.assertRaisesRegex(TypeError, errmsg, F, B)
        self.assertRaisesRegex(TypeError, errmsg, F, B())
        self.assertRaises(TypeError, F.from_number, B)
        self.assertRaises(TypeError, F.from_number, B())

    def testFromString(self):
        self.assertEqual((5, 1), _components(F("5")))