This notebook was prepared by Donne Martin. Source and license info is on GitHub.
* None input -> TypeError * negative input -> ValueError * 9 -> 9 * 138 -> 3 * 65536 -> 7
Refer to the Solution Notebook. If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.
class Solution(object):
def add_digits(self, val):
# TODO: Implement me
pass
The following unit test is expected to fail until you solve the challenge.
# %load test_add_digits.py
import unittest
class TestAddDigits(unittest.TestCase):
def test_add_digits(self, func):
self.assertRaises(TypeError, func, None)
self.assertRaises(ValueError, func, -1)
self.assertEqual(func(0), 0)
self.assertEqual(func(9), 9)
self.assertEqual(func(138), 3)
self.assertEqual(func(65536), 7)
print('Success: test_add_digits')
def main():
test = TestAddDigits()
solution = Solution()
test.test_add_digits(solution.add_digits)
try:
test.test_add_digits(solution.add_digits_optimized)
except AttributeError:
# Alternate solutions are only defined
# in the solutions file
pass
if __name__ == '__main__':
main()
Review the Solution Notebook for a discussion on algorithms and code solutions.