def __pow__(self, exp):
if not isinstance(exp, int):
raise TypeError("Exponent must be an integer.")
elif exp < 0:
return 1 / (self ** (-exp))
elif exp == 0:
return Polynomial("1")
elif not self:
return Polynomial()
elif self.is_monomial():
m = list(self.monomials[0])
m[0] = m[0] ** exp
m[1] = {l: e * exp for l, e in iteritems(m[1])}
return Polynomial.from_iterable([m])
elif self.is_binomial():
a = Polynomial.from_iterable([self._monomials[0]])
b = Polynomial.from_iterable([self._monomials[1]])
return sum(coeff * a ** (exp - k) * b ** k
for k, coeff in enumerate(bin_coeffs(exp)))
return functools.reduce(operator.mul, [self] * exp)
def test_bin_coeffs(self):
g1 = bin_coeffs(4)
g2 = bin_coeffs(n=5, start=1, stop=4, step=3)
g3 = bin_coeffs(3, 1, 3, 2)
g4 = bin_coeffs(4, 4, 1)
g5 = bin_coeffs(5, 4, 0, -2)
g6 = bin_coeffs(4)
g7 = bin_coeffs(5, 0, 3)
g8 = bin_coeffs(5, 2, 3)
self.assertEqual(g1.next(), 1)
self.assertEqual(g1.send(3), 4)
self.assertEqual(g1.send(0), 1)
self.assertEqual(list(g1), [4, 6, 4, 1])
self.assertIsInstance(g1, types.GeneratorType)
self.assertEqual(g2.next(), 5)
self.assertEqual(g2.next(), 5)
self.assertEqual(g2.send(3), 10)
self.assertRaises(StopIteration, g2.next)
self.assertIsInstance(g2, types.GeneratorType)
self.assertEqual(list(g3), [3, 1])
self.assertIsInstance(g3, types.GeneratorType)
g3 = bin_coeffs(3, 0, 3, 2)
self.assertEqual(list(g3), [1, 3])
self.assertEqual(list(g4), [1, 4, 6, 4])
self.assertEqual(list(g5), [5, 10, 1])
g6.next()
g7.next()
g8.next()
self.assertRaises(TypeError, g6.send, [])
g6 = bin_coeffs(4)
g6.next()
self.assertRaises(TypeError, g6.send, {})
g6 = bin_coeffs(4)
g6.next()
self.assertRaises(TypeError, g6.send, 1.5)
g6 = bin_coeffs(4)
g6.next()
self.assertRaises(ValueError, g6.send, -1)
g6 = bin_coeffs(4)
g6.next()
self.assertRaises(ValueError, g6.send, 5)
g6 = bin_coeffs(4)
g6.next()
self.assertRaises(ValueError, g7.send, 4)
g7 = bin_coeffs(5, 0, 3)
g7.next()
self.assertRaises(ValueError, g8.send, 1)
self.assertRaises(TypeError, bin_coeffs, 4, 1, 4, 5, 1)
self.assertRaises(TypeError, bin_coeffs, pippo=1)
self.assertRaises(TypeError, lambda x: bin_coeffs(x).next(), 1.5)
self.assertRaises(TypeError, lambda x: bin_coeffs(x).next(), [])
self.assertRaises(TypeError, lambda x: bin_coeffs(x).next(), {})
self.assertRaises(TypeError, lambda x: bin_coeffs(x).next())
self.assertRaises(ValueError, lambda x, y: bin_coeffs(x, y).next(),
4, 5)
self.assertRaises(ValueError,
lambda x, y, z, t: bin_coeffs(x, y, z, t).next(),
4, 1, 6, 2)
self.assertRaises(ValueError,
lambda x, y, z, t: bin_coeffs(x, y, z, t).next(),
4, 1, 4, 0)
self.assertRaises(ValueError,
lambda x, y, z: bin_coeffs(x, y, z).next(),
4, -1, 4)