def test_subtractBySelf(self):
a = Rational('2', '3')
b = Rational('2', '3')
result = a.__sub__(b)
self.assertEqual(result, Rational('0', '3'))
result = b.__sub__(a)
self.assertEqual(result, Rational('0', '3'))
def test_substractionOfTwoDifferentRationalNumbers(self):
a = Rational('2', '3')
b = Rational('5', '4')
result = a.__sub__(b)
self.assertEqual(result, Rational('-7', '12'))
result = b.__sub__(a)
self.assertEqual(result, Rational('7', '12'))
def test_substractionOfTwoNegativeDifferentIntegerRationalNumbers(self):
a = Rational('-2', '1')
b = Rational('-5', '1')
result = a.__sub__(b)
self.assertEqual(result, Rational('3', '1'))
result = b.__sub__(a)
self.assertEqual(result, Rational('-3', '1'))
def test_substractionOfIntegerRationalNumbers(self):
a = Rational('2', '1')
b = Rational('5', '1')
result = a.__sub__(b)
self.assertEqual(result, Rational(-3, 1))
result = b.__sub__(a)
self.assertEqual(result, Rational(3, 1))
def test_substractionOfNegativeAndPositiveDifferentRationalNumbers(self):
a = Rational('2', '3')
b = Rational('-5', '4')
result = a.__sub__(b)
self.assertEqual(result, Rational('23', '12'))
result = b.__sub__(a)
self.assertEqual(result, Rational('-23', '12'))
def test_substractionByZero(self):
a = Rational('4', '3')
b = Rational('0', '5')
c = Rational('2', '0')
d = Rational('2', '1')
e = Rational('0', '0')
self.assertRaises(a.__sub__(b), Rational('4', '3'))
self.assertRaises(b.__sub__(a), Rational('-4', '3'))
self.assertRaises(a.__sub__(c), Rational('4', '3'))
self.assertRaises(c.__sub__(a), Rational('-4', '3'))
self.assertRaises(d.__sub__(b), Rational('2', '1'))
self.assertRaises(b.__sub__(d), Rational('-2', '1'))
self.assertRaises(d.__sub__(c), Rational('2', '1'))
self.assertRaises(c.__sub__(d), Rational('-2', '1'))
self.assertRaises(a.__sub__(e), Rational('4', '3'))
self.assertRaises(e.__sub__(a), Rational('-4', '3'))
def test_subOfRationalNumberWithDifferentSignOfNumAndDino(self):
a = Rational('-2', '-3')
b = Rational('5', '4')
c = Rational('3', '-2')
d = Rational('-1,', '3')
result = a.__sub__(b)
self.assertEqual(result, Rational('-7', '12'))
result = b.__sub__(a)
self.assertEqual(result, Rational('7', '12'))
result = a.__sub__(c)
self.assertEqual(result, Rational('13', '6'))
result = c.__sub__(a)
self.assertEqual(result, Rational('-13', '6'))
result = a.__sub__(d)
self.assertEqual(result, Rational('-3', '3'))
result = d.__sub__(a)
self.assertEqual(result, Rational('-7', '6'))
result = b.__sub__(c)
self.assertEqual(result, Rational('11', '4'))
result = c.__sub__(b)
self.assertEqual(result, Rational('-11', '4'))
result = b.__sub__(d)
self.assertEqual(result, Rational('19', '12'))
result = d.__sub__(b)
self.assertEqual(result, Rational('-19', '12'))
result = c.__sub__(d)
self.assertEqual(result, Rational('-7', '6'))
result = d.__sub__(c)
self.assertEqual(result, Rational('7', '6'))