fancy_fizzbuzz.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''FizzBuzz library'''

from __future__ import unicode_literals


class FizzBuzzError(Exception):
    pass


def fizzbuzz(n):
    """FizzBuzz a number

    Parameters:
        n -- a number

    Returns 'Fizz' if n is divisible by 3, 'Buzz' if n is divisible by 5,
    'FizzBuzz' if n is divisble by both 3 and 5.

    Raises a FizzBuzzError if n is not divisible either 3 or 5.
    """
    if not n % 3:
        if not n % 5:
            return 'FizzBuzz'
        return 'Fizz'
    elif not n % 5:
        return 'Buzz'
    else:
        raise FizzBuzzError


def fizzbuzz_range(start, stop, step=1):
    """FizzBuzz a range of numbers

    Parameters:
        start -- the start of the range of numbers to fizzbuzz (inclusive)
        stop -- the end of the range of numbers to fizzbuzz (exclusive)
        step -- the interval of numbers to fizzbuzz

    Returns a list of strings containing the fizzbuzz results
    """
    result = []
    for i in range(start, stop, step):
        try:
            result.append(fizzbuzz(i))
        except FizzBuzzError:
            result.append(unicode(i))
    return result


def main():
    from argparse import ArgumentParser

    parser = ArgumentParser(description='Run fizzbuzz on a range of numbers')
    parser.add_argument('start', type=int,
                        help='Start of the range (inclusive)')
    parser.add_argument('stop', type=int,
                        help='End of the range (exclusive)')
    parser.add_argument('step', type=int, nargs='?', default=1)
    args = parser.parse_args()

    for s in fizzbuzz_range(args.start, args.stop, args.step):
        print s


if __name__ == '__main__':
    main()

test_fizzbuzz.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''Tests for FizzBuzz library'''

from __future__ import unicode_literals, absolute_import

import unittest
from fancy_fizzbuzz import FizzBuzzError, fizzbuzz, fizzbuzz_range


class TestFizzBuzz(unittest.TestCase):

    def test_fizzbuzz(self):
        self.assertEqual(fizzbuzz(3), 'Fizz')
        self.assertEqual(fizzbuzz(5), 'Buzz')
        self.assertEqual(fizzbuzz(15), 'FizzBuzz')
        with self.assertRaises(FizzBuzzError):
            fizzbuzz(1)

    def test_fizzbuzz_range(self):
        self.assertEqual(
            fizzbuzz_range(1, 6, 1),
            ['1', '2', 'Fizz', '4', 'Buzz']
        )
        self.assertEqual(
            fizzbuzz_range(10, 20, 5),
            ['Buzz', 'FizzBuzz']
        )


if __name__ == '__main__':
    unittest.main()