Dojo atualizado :D

feliz.py

def feliz(number, results=None):
    if results is None:
        results = []

    next_number = sum(int(a) ** 2 for a in str(number))

    if next_number in results:
        return False

    if next_number != 1:
        results.append(next_number)
        return feliz(next_number, results)
    else:
        return True

test_feliz.py

import unittest

from feliz import feliz


class FelizTestCase(unittest.TestCase):

    def test_7(self):
        self.assertTrue(feliz(7))

    def test_49(self):
        self.assertTrue(feliz(49))

    def test_3(self):
        self.assertFalse(feliz(3))

    def test_6(self):
        self.assertFalse(feliz(6))