Manage a game player's High Score list.
Your task is to build a high-score component of the classic Frogger game, one of the highest selling and addictive games of all time, and a classic of the arcade era. Your task is to write methods that return the highest score from the list, the last added score and the three highest scores.
In this exercise, you're going to use and manipulate lists. Python lists are very versatile, and you'll find yourself using them again and again in problems both simple and complex.
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")
To run the tests, run
Alternatively, you can tell Python to run the pytest module:
python -m pytest high_scores_test.py
-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
Note that, when trying to submit an exercise, make sure the solution is in the
You can find your Exercism workspace by running
exercism debug and looking for the line that starts with
For more detailed information about running tests, code style and linting, please see Running the Tests.
Tribute to the eighties' arcade game Frogger
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
import unittest from high_scores import latest, personal_best, personal_top_three # Tests adapted from `problem-specifications//canonical-data.json` class HighScoresTest(unittest.TestCase): def test_latest_score(self): scores = [100, 0, 90, 30] expected = 30 self.assertEqual(latest(scores), expected) def test_personal_best(self): scores = [40, 100, 70] expected = 100 self.assertEqual(personal_best(scores), expected) def test_personal_top_three_from_a_list_of_scores(self): scores = [10, 30, 90, 30, 100, 20, 10, 0, 30, 40, 40, 70, 70] expected = [100, 90, 70] self.assertEqual(personal_top_three(scores), expected) def test_personal_top_highest_to_lowest(self): scores = [20, 10, 30] expected = [30, 20, 10] self.assertEqual(personal_top_three(scores), expected) def test_personal_top_when_there_is_a_tie(self): scores = [40, 20, 40, 30] expected = [40, 40, 30] self.assertEqual(personal_top_three(scores), expected) def test_personal_top_when_there_are_less_than_3(self): scores = [30, 70] expected = [70, 30] self.assertEqual(personal_top_three(scores), expected) def test_personal_top_when_there_is_only_one(self): scores =  expected =  self.assertEqual(personal_top_three(scores), expected) if __name__ == "__main__": unittest.main()
def latest(scores): return scores[-1] def personal_best(scores): return max(scores) def personal_top_three(scores): return sorted(scores, reverse=True)[:3]
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.