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nicolemon's solution

to Beer Song in the Python Track

Published at Jul 21 2018 · 0 comments
Instructions
Test suite
Solution

Note:

This exercise has changed since this solution was written.

Recite the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.

Note that not all verses are identical.

99 bottles of beer on the wall, 99 bottles of beer.
Take one down and pass it around, 98 bottles of beer on the wall.

98 bottles of beer on the wall, 98 bottles of beer.
Take one down and pass it around, 97 bottles of beer on the wall.

97 bottles of beer on the wall, 97 bottles of beer.
Take one down and pass it around, 96 bottles of beer on the wall.

96 bottles of beer on the wall, 96 bottles of beer.
Take one down and pass it around, 95 bottles of beer on the wall.

95 bottles of beer on the wall, 95 bottles of beer.
Take one down and pass it around, 94 bottles of beer on the wall.

94 bottles of beer on the wall, 94 bottles of beer.
Take one down and pass it around, 93 bottles of beer on the wall.

93 bottles of beer on the wall, 93 bottles of beer.
Take one down and pass it around, 92 bottles of beer on the wall.

92 bottles of beer on the wall, 92 bottles of beer.
Take one down and pass it around, 91 bottles of beer on the wall.

91 bottles of beer on the wall, 91 bottles of beer.
Take one down and pass it around, 90 bottles of beer on the wall.

90 bottles of beer on the wall, 90 bottles of beer.
Take one down and pass it around, 89 bottles of beer on the wall.

89 bottles of beer on the wall, 89 bottles of beer.
Take one down and pass it around, 88 bottles of beer on the wall.

88 bottles of beer on the wall, 88 bottles of beer.
Take one down and pass it around, 87 bottles of beer on the wall.

87 bottles of beer on the wall, 87 bottles of beer.
Take one down and pass it around, 86 bottles of beer on the wall.

86 bottles of beer on the wall, 86 bottles of beer.
Take one down and pass it around, 85 bottles of beer on the wall.

85 bottles of beer on the wall, 85 bottles of beer.
Take one down and pass it around, 84 bottles of beer on the wall.

84 bottles of beer on the wall, 84 bottles of beer.
Take one down and pass it around, 83 bottles of beer on the wall.

83 bottles of beer on the wall, 83 bottles of beer.
Take one down and pass it around, 82 bottles of beer on the wall.

82 bottles of beer on the wall, 82 bottles of beer.
Take one down and pass it around, 81 bottles of beer on the wall.

81 bottles of beer on the wall, 81 bottles of beer.
Take one down and pass it around, 80 bottles of beer on the wall.

80 bottles of beer on the wall, 80 bottles of beer.
Take one down and pass it around, 79 bottles of beer on the wall.

79 bottles of beer on the wall, 79 bottles of beer.
Take one down and pass it around, 78 bottles of beer on the wall.

78 bottles of beer on the wall, 78 bottles of beer.
Take one down and pass it around, 77 bottles of beer on the wall.

77 bottles of beer on the wall, 77 bottles of beer.
Take one down and pass it around, 76 bottles of beer on the wall.

76 bottles of beer on the wall, 76 bottles of beer.
Take one down and pass it around, 75 bottles of beer on the wall.

75 bottles of beer on the wall, 75 bottles of beer.
Take one down and pass it around, 74 bottles of beer on the wall.

74 bottles of beer on the wall, 74 bottles of beer.
Take one down and pass it around, 73 bottles of beer on the wall.

73 bottles of beer on the wall, 73 bottles of beer.
Take one down and pass it around, 72 bottles of beer on the wall.

72 bottles of beer on the wall, 72 bottles of beer.
Take one down and pass it around, 71 bottles of beer on the wall.

71 bottles of beer on the wall, 71 bottles of beer.
Take one down and pass it around, 70 bottles of beer on the wall.

70 bottles of beer on the wall, 70 bottles of beer.
Take one down and pass it around, 69 bottles of beer on the wall.

69 bottles of beer on the wall, 69 bottles of beer.
Take one down and pass it around, 68 bottles of beer on the wall.

68 bottles of beer on the wall, 68 bottles of beer.
Take one down and pass it around, 67 bottles of beer on the wall.

67 bottles of beer on the wall, 67 bottles of beer.
Take one down and pass it around, 66 bottles of beer on the wall.

66 bottles of beer on the wall, 66 bottles of beer.
Take one down and pass it around, 65 bottles of beer on the wall.

65 bottles of beer on the wall, 65 bottles of beer.
Take one down and pass it around, 64 bottles of beer on the wall.

64 bottles of beer on the wall, 64 bottles of beer.
Take one down and pass it around, 63 bottles of beer on the wall.

63 bottles of beer on the wall, 63 bottles of beer.
Take one down and pass it around, 62 bottles of beer on the wall.

62 bottles of beer on the wall, 62 bottles of beer.
Take one down and pass it around, 61 bottles of beer on the wall.

61 bottles of beer on the wall, 61 bottles of beer.
Take one down and pass it around, 60 bottles of beer on the wall.

60 bottles of beer on the wall, 60 bottles of beer.
Take one down and pass it around, 59 bottles of beer on the wall.

59 bottles of beer on the wall, 59 bottles of beer.
Take one down and pass it around, 58 bottles of beer on the wall.

58 bottles of beer on the wall, 58 bottles of beer.
Take one down and pass it around, 57 bottles of beer on the wall.

57 bottles of beer on the wall, 57 bottles of beer.
Take one down and pass it around, 56 bottles of beer on the wall.

56 bottles of beer on the wall, 56 bottles of beer.
Take one down and pass it around, 55 bottles of beer on the wall.

55 bottles of beer on the wall, 55 bottles of beer.
Take one down and pass it around, 54 bottles of beer on the wall.

54 bottles of beer on the wall, 54 bottles of beer.
Take one down and pass it around, 53 bottles of beer on the wall.

53 bottles of beer on the wall, 53 bottles of beer.
Take one down and pass it around, 52 bottles of beer on the wall.

52 bottles of beer on the wall, 52 bottles of beer.
Take one down and pass it around, 51 bottles of beer on the wall.

51 bottles of beer on the wall, 51 bottles of beer.
Take one down and pass it around, 50 bottles of beer on the wall.

50 bottles of beer on the wall, 50 bottles of beer.
Take one down and pass it around, 49 bottles of beer on the wall.

49 bottles of beer on the wall, 49 bottles of beer.
Take one down and pass it around, 48 bottles of beer on the wall.

48 bottles of beer on the wall, 48 bottles of beer.
Take one down and pass it around, 47 bottles of beer on the wall.

47 bottles of beer on the wall, 47 bottles of beer.
Take one down and pass it around, 46 bottles of beer on the wall.

46 bottles of beer on the wall, 46 bottles of beer.
Take one down and pass it around, 45 bottles of beer on the wall.

45 bottles of beer on the wall, 45 bottles of beer.
Take one down and pass it around, 44 bottles of beer on the wall.

44 bottles of beer on the wall, 44 bottles of beer.
Take one down and pass it around, 43 bottles of beer on the wall.

43 bottles of beer on the wall, 43 bottles of beer.
Take one down and pass it around, 42 bottles of beer on the wall.

42 bottles of beer on the wall, 42 bottles of beer.
Take one down and pass it around, 41 bottles of beer on the wall.

41 bottles of beer on the wall, 41 bottles of beer.
Take one down and pass it around, 40 bottles of beer on the wall.

40 bottles of beer on the wall, 40 bottles of beer.
Take one down and pass it around, 39 bottles of beer on the wall.

39 bottles of beer on the wall, 39 bottles of beer.
Take one down and pass it around, 38 bottles of beer on the wall.

38 bottles of beer on the wall, 38 bottles of beer.
Take one down and pass it around, 37 bottles of beer on the wall.

37 bottles of beer on the wall, 37 bottles of beer.
Take one down and pass it around, 36 bottles of beer on the wall.

36 bottles of beer on the wall, 36 bottles of beer.
Take one down and pass it around, 35 bottles of beer on the wall.

35 bottles of beer on the wall, 35 bottles of beer.
Take one down and pass it around, 34 bottles of beer on the wall.

34 bottles of beer on the wall, 34 bottles of beer.
Take one down and pass it around, 33 bottles of beer on the wall.

33 bottles of beer on the wall, 33 bottles of beer.
Take one down and pass it around, 32 bottles of beer on the wall.

32 bottles of beer on the wall, 32 bottles of beer.
Take one down and pass it around, 31 bottles of beer on the wall.

31 bottles of beer on the wall, 31 bottles of beer.
Take one down and pass it around, 30 bottles of beer on the wall.

30 bottles of beer on the wall, 30 bottles of beer.
Take one down and pass it around, 29 bottles of beer on the wall.

29 bottles of beer on the wall, 29 bottles of beer.
Take one down and pass it around, 28 bottles of beer on the wall.

28 bottles of beer on the wall, 28 bottles of beer.
Take one down and pass it around, 27 bottles of beer on the wall.

27 bottles of beer on the wall, 27 bottles of beer.
Take one down and pass it around, 26 bottles of beer on the wall.

26 bottles of beer on the wall, 26 bottles of beer.
Take one down and pass it around, 25 bottles of beer on the wall.

25 bottles of beer on the wall, 25 bottles of beer.
Take one down and pass it around, 24 bottles of beer on the wall.

24 bottles of beer on the wall, 24 bottles of beer.
Take one down and pass it around, 23 bottles of beer on the wall.

23 bottles of beer on the wall, 23 bottles of beer.
Take one down and pass it around, 22 bottles of beer on the wall.

22 bottles of beer on the wall, 22 bottles of beer.
Take one down and pass it around, 21 bottles of beer on the wall.

21 bottles of beer on the wall, 21 bottles of beer.
Take one down and pass it around, 20 bottles of beer on the wall.

20 bottles of beer on the wall, 20 bottles of beer.
Take one down and pass it around, 19 bottles of beer on the wall.

19 bottles of beer on the wall, 19 bottles of beer.
Take one down and pass it around, 18 bottles of beer on the wall.

18 bottles of beer on the wall, 18 bottles of beer.
Take one down and pass it around, 17 bottles of beer on the wall.

17 bottles of beer on the wall, 17 bottles of beer.
Take one down and pass it around, 16 bottles of beer on the wall.

16 bottles of beer on the wall, 16 bottles of beer.
Take one down and pass it around, 15 bottles of beer on the wall.

15 bottles of beer on the wall, 15 bottles of beer.
Take one down and pass it around, 14 bottles of beer on the wall.

14 bottles of beer on the wall, 14 bottles of beer.
Take one down and pass it around, 13 bottles of beer on the wall.

13 bottles of beer on the wall, 13 bottles of beer.
Take one down and pass it around, 12 bottles of beer on the wall.

12 bottles of beer on the wall, 12 bottles of beer.
Take one down and pass it around, 11 bottles of beer on the wall.

11 bottles of beer on the wall, 11 bottles of beer.
Take one down and pass it around, 10 bottles of beer on the wall.

10 bottles of beer on the wall, 10 bottles of beer.
Take one down and pass it around, 9 bottles of beer on the wall.

9 bottles of beer on the wall, 9 bottles of beer.
Take one down and pass it around, 8 bottles of beer on the wall.

8 bottles of beer on the wall, 8 bottles of beer.
Take one down and pass it around, 7 bottles of beer on the wall.

7 bottles of beer on the wall, 7 bottles of beer.
Take one down and pass it around, 6 bottles of beer on the wall.

6 bottles of beer on the wall, 6 bottles of beer.
Take one down and pass it around, 5 bottles of beer on the wall.

5 bottles of beer on the wall, 5 bottles of beer.
Take one down and pass it around, 4 bottles of beer on the wall.

4 bottles of beer on the wall, 4 bottles of beer.
Take one down and pass it around, 3 bottles of beer on the wall.

3 bottles of beer on the wall, 3 bottles of beer.
Take one down and pass it around, 2 bottles of beer on the wall.

2 bottles of beer on the wall, 2 bottles of beer.
Take one down and pass it around, 1 bottle of beer on the wall.

1 bottle of beer on the wall, 1 bottle of beer.
Take it down and pass it around, no more bottles of beer on the wall.

No more bottles of beer on the wall, no more bottles of beer.
Go to the store and buy some more, 99 bottles of beer on the wall.

For bonus points

Did you get the tests passing and the code clean? If you want to, these are some additional things you could try:

  • Remove as much duplication as you possibly can.
  • Optimize for readability, even if it means introducing duplication.
  • If you've removed all the duplication, do you have a lot of conditionals? Try replacing the conditionals with polymorphism, if it applies in this language. How readable is it?

Then please share your thoughts in a comment on the submission. Did this experiment make the code better? Worse? Did you learn anything from it?

Exception messages

Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include a message.

To raise a message with an exception, just write it as an argument to the exception type. For example, instead of raise Exception, you should write:

raise Exception("Meaningful message indicating the source of the error")

Running the tests

To run the tests, run the appropriate command below (why they are different):

  • Python 2.7: py.test beer_song_test.py
  • Python 3.4+: pytest beer_song_test.py

Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version): python -m pytest beer_song_test.py

Common pytest options

  • -v : enable verbose output
  • -x : stop running tests on first failure
  • --ff : run failures from previous test before running other test cases

For other options, see python -m pytest -h

Submitting Exercises

Note that, when trying to submit an exercise, make sure the solution is in the $EXERCISM_WORKSPACE/python/beer-song directory.

You can find your Exercism workspace by running exercism debug and looking for the line that starts with Workspace.

For more detailed information about running tests, code style and linting, please see Running the Tests.

Source

Learn to Program by Chris Pine http://pine.fm/LearnToProgram/?Chapter=06

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

beer_song_test.py

import unittest

from beer_song import recite


# Tests adapted from `problem-specifications//canonical-data.json` @ v2.1.0

class BeerSongTest(unittest.TestCase):
    def test_first_generic_verse(self):
        expected = [
            "99 bottles of beer on the wall, 99 bottles of beer.",
            "Take one down and pass it around, 98 bottles of beer on the wall."
        ]
        self.assertEqual(recite(start=99), expected)

    def test_last_generic_verse(self):
        expected = [
            "3 bottles of beer on the wall, 3 bottles of beer.",
            "Take one down and pass it around, 2 bottles of beer on the wall."
        ]
        self.assertEqual(recite(start=3), expected)

    def test_verse_with_two_bottles(self):
        expected = [
            "2 bottles of beer on the wall, 2 bottles of beer.",
            "Take one down and pass it around, 1 bottle of beer on the wall."
        ]
        self.assertEqual(recite(start=2), expected)

    def test_verse_with_one_bottle(self):
        expected = [
            "1 bottle of beer on the wall, 1 bottle of beer.",
            (
                "Take it down and pass it around, "
                "no more bottles of beer on the wall."
            )
        ]
        self.assertEqual(recite(start=1), expected)

    def test_verse_with_zero_bottles(self):
        expected = [
            "No more bottles of beer on the wall, no more bottles of beer.",
            (
                "Go to the store and buy some more, "
                "99 bottles of beer on the wall."
            )
        ]
        self.assertEqual(recite(start=0), expected)

    def test_first_two_verses(self):
        expected = [
            "99 bottles of beer on the wall, 99 bottles of beer.",
            (
                "Take one down and pass it around, "
                "98 bottles of beer on the wall."
            ),
            "",
            "98 bottles of beer on the wall, 98 bottles of beer.",
            "Take one down and pass it around, 97 bottles of beer on the wall."
        ]
        self.assertEqual(recite(start=99, take=2), expected)

    def test_last_three_verses(self):
        expected = [
            "2 bottles of beer on the wall, 2 bottles of beer.",
            "Take one down and pass it around, 1 bottle of beer on the wall.",
            "",
            "1 bottle of beer on the wall, 1 bottle of beer.",
            (
                "Take it down and pass it around, "
                "no more bottles of beer on the wall."
            ),
            "",
            "No more bottles of beer on the wall, no more bottles of beer.",
            (
                "Go to the store and buy some more, "
                "99 bottles of beer on the wall."
            )
        ]
        self.assertEqual(recite(start=2, take=3), expected)

    def test_all_verses(self):
        self.assertEqual(recite(start=99, take=100), SONG)


SONG = [
    "99 bottles of beer on the wall, 99 bottles of beer.",
    "Take one down and pass it around, 98 bottles of beer on the wall.",
    "",
    "98 bottles of beer on the wall, 98 bottles of beer.",
    "Take one down and pass it around, 97 bottles of beer on the wall.",
    "",
    "97 bottles of beer on the wall, 97 bottles of beer.",
    "Take one down and pass it around, 96 bottles of beer on the wall.",
    "",
    "96 bottles of beer on the wall, 96 bottles of beer.",
    "Take one down and pass it around, 95 bottles of beer on the wall.",
    "",
    "95 bottles of beer on the wall, 95 bottles of beer.",
    "Take one down and pass it around, 94 bottles of beer on the wall.",
    "",
    "94 bottles of beer on the wall, 94 bottles of beer.",
    "Take one down and pass it around, 93 bottles of beer on the wall.",
    "",
    "93 bottles of beer on the wall, 93 bottles of beer.",
    "Take one down and pass it around, 92 bottles of beer on the wall.",
    "",
    "92 bottles of beer on the wall, 92 bottles of beer.",
    "Take one down and pass it around, 91 bottles of beer on the wall.",
    "",
    "91 bottles of beer on the wall, 91 bottles of beer.",
    "Take one down and pass it around, 90 bottles of beer on the wall.",
    "",
    "90 bottles of beer on the wall, 90 bottles of beer.",
    "Take one down and pass it around, 89 bottles of beer on the wall.",
    "",
    "89 bottles of beer on the wall, 89 bottles of beer.",
    "Take one down and pass it around, 88 bottles of beer on the wall.",
    "",
    "88 bottles of beer on the wall, 88 bottles of beer.",
    "Take one down and pass it around, 87 bottles of beer on the wall.",
    "",
    "87 bottles of beer on the wall, 87 bottles of beer.",
    "Take one down and pass it around, 86 bottles of beer on the wall.",
    "",
    "86 bottles of beer on the wall, 86 bottles of beer.",
    "Take one down and pass it around, 85 bottles of beer on the wall.",
    "",
    "85 bottles of beer on the wall, 85 bottles of beer.",
    "Take one down and pass it around, 84 bottles of beer on the wall.",
    "",
    "84 bottles of beer on the wall, 84 bottles of beer.",
    "Take one down and pass it around, 83 bottles of beer on the wall.",
    "",
    "83 bottles of beer on the wall, 83 bottles of beer.",
    "Take one down and pass it around, 82 bottles of beer on the wall.",
    "",
    "82 bottles of beer on the wall, 82 bottles of beer.",
    "Take one down and pass it around, 81 bottles of beer on the wall.",
    "",
    "81 bottles of beer on the wall, 81 bottles of beer.",
    "Take one down and pass it around, 80 bottles of beer on the wall.",
    "",
    "80 bottles of beer on the wall, 80 bottles of beer.",
    "Take one down and pass it around, 79 bottles of beer on the wall.",
    "",
    "79 bottles of beer on the wall, 79 bottles of beer.",
    "Take one down and pass it around, 78 bottles of beer on the wall.",
    "",
    "78 bottles of beer on the wall, 78 bottles of beer.",
    "Take one down and pass it around, 77 bottles of beer on the wall.",
    "",
    "77 bottles of beer on the wall, 77 bottles of beer.",
    "Take one down and pass it around, 76 bottles of beer on the wall.",
    "",
    "76 bottles of beer on the wall, 76 bottles of beer.",
    "Take one down and pass it around, 75 bottles of beer on the wall.",
    "",
    "75 bottles of beer on the wall, 75 bottles of beer.",
    "Take one down and pass it around, 74 bottles of beer on the wall.",
    "",
    "74 bottles of beer on the wall, 74 bottles of beer.",
    "Take one down and pass it around, 73 bottles of beer on the wall.",
    "",
    "73 bottles of beer on the wall, 73 bottles of beer.",
    "Take one down and pass it around, 72 bottles of beer on the wall.",
    "",
    "72 bottles of beer on the wall, 72 bottles of beer.",
    "Take one down and pass it around, 71 bottles of beer on the wall.",
    "",
    "71 bottles of beer on the wall, 71 bottles of beer.",
    "Take one down and pass it around, 70 bottles of beer on the wall.",
    "",
    "70 bottles of beer on the wall, 70 bottles of beer.",
    "Take one down and pass it around, 69 bottles of beer on the wall.",
    "",
    "69 bottles of beer on the wall, 69 bottles of beer.",
    "Take one down and pass it around, 68 bottles of beer on the wall.",
    "",
    "68 bottles of beer on the wall, 68 bottles of beer.",
    "Take one down and pass it around, 67 bottles of beer on the wall.",
    "",
    "67 bottles of beer on the wall, 67 bottles of beer.",
    "Take one down and pass it around, 66 bottles of beer on the wall.",
    "",
    "66 bottles of beer on the wall, 66 bottles of beer.",
    "Take one down and pass it around, 65 bottles of beer on the wall.",
    "",
    "65 bottles of beer on the wall, 65 bottles of beer.",
    "Take one down and pass it around, 64 bottles of beer on the wall.",
    "",
    "64 bottles of beer on the wall, 64 bottles of beer.",
    "Take one down and pass it around, 63 bottles of beer on the wall.",
    "",
    "63 bottles of beer on the wall, 63 bottles of beer.",
    "Take one down and pass it around, 62 bottles of beer on the wall.",
    "",
    "62 bottles of beer on the wall, 62 bottles of beer.",
    "Take one down and pass it around, 61 bottles of beer on the wall.",
    "",
    "61 bottles of beer on the wall, 61 bottles of beer.",
    "Take one down and pass it around, 60 bottles of beer on the wall.",
    "",
    "60 bottles of beer on the wall, 60 bottles of beer.",
    "Take one down and pass it around, 59 bottles of beer on the wall.",
    "",
    "59 bottles of beer on the wall, 59 bottles of beer.",
    "Take one down and pass it around, 58 bottles of beer on the wall.",
    "",
    "58 bottles of beer on the wall, 58 bottles of beer.",
    "Take one down and pass it around, 57 bottles of beer on the wall.",
    "",
    "57 bottles of beer on the wall, 57 bottles of beer.",
    "Take one down and pass it around, 56 bottles of beer on the wall.",
    "",
    "56 bottles of beer on the wall, 56 bottles of beer.",
    "Take one down and pass it around, 55 bottles of beer on the wall.",
    "",
    "55 bottles of beer on the wall, 55 bottles of beer.",
    "Take one down and pass it around, 54 bottles of beer on the wall.",
    "",
    "54 bottles of beer on the wall, 54 bottles of beer.",
    "Take one down and pass it around, 53 bottles of beer on the wall.",
    "",
    "53 bottles of beer on the wall, 53 bottles of beer.",
    "Take one down and pass it around, 52 bottles of beer on the wall.",
    "",
    "52 bottles of beer on the wall, 52 bottles of beer.",
    "Take one down and pass it around, 51 bottles of beer on the wall.",
    "",
    "51 bottles of beer on the wall, 51 bottles of beer.",
    "Take one down and pass it around, 50 bottles of beer on the wall.",
    "",
    "50 bottles of beer on the wall, 50 bottles of beer.",
    "Take one down and pass it around, 49 bottles of beer on the wall.",
    "",
    "49 bottles of beer on the wall, 49 bottles of beer.",
    "Take one down and pass it around, 48 bottles of beer on the wall.",
    "",
    "48 bottles of beer on the wall, 48 bottles of beer.",
    "Take one down and pass it around, 47 bottles of beer on the wall.",
    "",
    "47 bottles of beer on the wall, 47 bottles of beer.",
    "Take one down and pass it around, 46 bottles of beer on the wall.",
    "",
    "46 bottles of beer on the wall, 46 bottles of beer.",
    "Take one down and pass it around, 45 bottles of beer on the wall.",
    "",
    "45 bottles of beer on the wall, 45 bottles of beer.",
    "Take one down and pass it around, 44 bottles of beer on the wall.",
    "",
    "44 bottles of beer on the wall, 44 bottles of beer.",
    "Take one down and pass it around, 43 bottles of beer on the wall.",
    "",
    "43 bottles of beer on the wall, 43 bottles of beer.",
    "Take one down and pass it around, 42 bottles of beer on the wall.",
    "",
    "42 bottles of beer on the wall, 42 bottles of beer.",
    "Take one down and pass it around, 41 bottles of beer on the wall.",
    "",
    "41 bottles of beer on the wall, 41 bottles of beer.",
    "Take one down and pass it around, 40 bottles of beer on the wall.",
    "",
    "40 bottles of beer on the wall, 40 bottles of beer.",
    "Take one down and pass it around, 39 bottles of beer on the wall.",
    "",
    "39 bottles of beer on the wall, 39 bottles of beer.",
    "Take one down and pass it around, 38 bottles of beer on the wall.",
    "",
    "38 bottles of beer on the wall, 38 bottles of beer.",
    "Take one down and pass it around, 37 bottles of beer on the wall.",
    "",
    "37 bottles of beer on the wall, 37 bottles of beer.",
    "Take one down and pass it around, 36 bottles of beer on the wall.",
    "",
    "36 bottles of beer on the wall, 36 bottles of beer.",
    "Take one down and pass it around, 35 bottles of beer on the wall.",
    "",
    "35 bottles of beer on the wall, 35 bottles of beer.",
    "Take one down and pass it around, 34 bottles of beer on the wall.",
    "",
    "34 bottles of beer on the wall, 34 bottles of beer.",
    "Take one down and pass it around, 33 bottles of beer on the wall.",
    "",
    "33 bottles of beer on the wall, 33 bottles of beer.",
    "Take one down and pass it around, 32 bottles of beer on the wall.",
    "",
    "32 bottles of beer on the wall, 32 bottles of beer.",
    "Take one down and pass it around, 31 bottles of beer on the wall.",
    "",
    "31 bottles of beer on the wall, 31 bottles of beer.",
    "Take one down and pass it around, 30 bottles of beer on the wall.",
    "",
    "30 bottles of beer on the wall, 30 bottles of beer.",
    "Take one down and pass it around, 29 bottles of beer on the wall.",
    "",
    "29 bottles of beer on the wall, 29 bottles of beer.",
    "Take one down and pass it around, 28 bottles of beer on the wall.",
    "",
    "28 bottles of beer on the wall, 28 bottles of beer.",
    "Take one down and pass it around, 27 bottles of beer on the wall.",
    "",
    "27 bottles of beer on the wall, 27 bottles of beer.",
    "Take one down and pass it around, 26 bottles of beer on the wall.",
    "",
    "26 bottles of beer on the wall, 26 bottles of beer.",
    "Take one down and pass it around, 25 bottles of beer on the wall.",
    "",
    "25 bottles of beer on the wall, 25 bottles of beer.",
    "Take one down and pass it around, 24 bottles of beer on the wall.",
    "",
    "24 bottles of beer on the wall, 24 bottles of beer.",
    "Take one down and pass it around, 23 bottles of beer on the wall.",
    "",
    "23 bottles of beer on the wall, 23 bottles of beer.",
    "Take one down and pass it around, 22 bottles of beer on the wall.",
    "",
    "22 bottles of beer on the wall, 22 bottles of beer.",
    "Take one down and pass it around, 21 bottles of beer on the wall.",
    "",
    "21 bottles of beer on the wall, 21 bottles of beer.",
    "Take one down and pass it around, 20 bottles of beer on the wall.",
    "",
    "20 bottles of beer on the wall, 20 bottles of beer.",
    "Take one down and pass it around, 19 bottles of beer on the wall.",
    "",
    "19 bottles of beer on the wall, 19 bottles of beer.",
    "Take one down and pass it around, 18 bottles of beer on the wall.",
    "",
    "18 bottles of beer on the wall, 18 bottles of beer.",
    "Take one down and pass it around, 17 bottles of beer on the wall.",
    "",
    "17 bottles of beer on the wall, 17 bottles of beer.",
    "Take one down and pass it around, 16 bottles of beer on the wall.",
    "",
    "16 bottles of beer on the wall, 16 bottles of beer.",
    "Take one down and pass it around, 15 bottles of beer on the wall.",
    "",
    "15 bottles of beer on the wall, 15 bottles of beer.",
    "Take one down and pass it around, 14 bottles of beer on the wall.",
    "",
    "14 bottles of beer on the wall, 14 bottles of beer.",
    "Take one down and pass it around, 13 bottles of beer on the wall.",
    "",
    "13 bottles of beer on the wall, 13 bottles of beer.",
    "Take one down and pass it around, 12 bottles of beer on the wall.",
    "",
    "12 bottles of beer on the wall, 12 bottles of beer.",
    "Take one down and pass it around, 11 bottles of beer on the wall.",
    "",
    "11 bottles of beer on the wall, 11 bottles of beer.",
    "Take one down and pass it around, 10 bottles of beer on the wall.",
    "",
    "10 bottles of beer on the wall, 10 bottles of beer.",
    "Take one down and pass it around, 9 bottles of beer on the wall.",
    "",
    "9 bottles of beer on the wall, 9 bottles of beer.",
    "Take one down and pass it around, 8 bottles of beer on the wall.",
    "",
    "8 bottles of beer on the wall, 8 bottles of beer.",
    "Take one down and pass it around, 7 bottles of beer on the wall.",
    "",
    "7 bottles of beer on the wall, 7 bottles of beer.",
    "Take one down and pass it around, 6 bottles of beer on the wall.",
    "",
    "6 bottles of beer on the wall, 6 bottles of beer.",
    "Take one down and pass it around, 5 bottles of beer on the wall.",
    "",
    "5 bottles of beer on the wall, 5 bottles of beer.",
    "Take one down and pass it around, 4 bottles of beer on the wall.",
    "",
    "4 bottles of beer on the wall, 4 bottles of beer.",
    "Take one down and pass it around, 3 bottles of beer on the wall.",
    "",
    "3 bottles of beer on the wall, 3 bottles of beer.",
    "Take one down and pass it around, 2 bottles of beer on the wall.",
    "",
    "2 bottles of beer on the wall, 2 bottles of beer.",
    "Take one down and pass it around, 1 bottle of beer on the wall.",
    "",
    "1 bottle of beer on the wall, 1 bottle of beer.",
    "Take it down and pass it around, no more bottles of beer on the wall.",
    "",
    "No more bottles of beer on the wall, no more bottles of beer.",
    "Go to the store and buy some more, 99 bottles of beer on the wall."
]


if __name__ == '__main__':
    unittest.main()
ONE_BOTTLE = '1 bottle of beer'
N_BOTTLES = '{n} bottles of beer'
WHERE = 'on the wall'
DO_WHAT = 'Take {what} down and pass it around'
DO_WHAT_NOW = 'Go to the store and buy some more'

def _build_verse(num):

    num = int(num)
    if num == 0:
        bottle = N_BOTTLES.format(n='no more')
        action = DO_WHAT_NOW
        result = N_BOTTLES.format(n='99')
    elif num == 1:
        bottle = ONE_BOTTLE
        action = DO_WHAT.format(what='it')
        result = N_BOTTLES.format(n='no more')
    else:
        bottle = N_BOTTLES.format(n=str(num))
        action = DO_WHAT.format(what='one')
        if num == 2:
            result = ONE_BOTTLE
        else:
            result = N_BOTTLES.format(n=str(num-1))

    line1a = ' '.join([bottle, WHERE])
    line1 = ', '.join([line1a, bottle])
    line1 = '{}.'.format(line1.capitalize())

    line2b = ' '.join([result, WHERE])
    line2 = ', '.join([action, line2b])
    line2 = '{}.'.format(line2)

    return [line1, line2]


def recite(start, take=1):

    verses = []
    num = start
    while take > 0:
        verse = _build_verse(num)
        verses.extend(verse)
        num -= 1
        take -= 1
        if take > 0:  # ew gross
            verses.append('')

    return verses

Community comments

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nicolemon's Reflection

a little unwieldy but it works