clock exercise

python/clock/.exercism/metadata.json

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+{"track":"python","exercise":"clock","id":"5ea6c6c4c840489da2850d5d3dacd63f","url":"https://exercism.io/my/solutions/5ea6c6c4c840489da2850d5d3dacd63f","handle":"Xevion","is_requester":true,"auto_approve":false}

python/clock/README.md

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+# Clock
+
+Implement a clock that handles times without dates.
+
+You should be able to add and subtract minutes to it.
+
+Two clocks that represent the same time should be equal to each other.
+
+## 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:
+
+```python
+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](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):
+
+- Python 2.7: `py.test clock_test.py`
+- Python 3.4+: `pytest clock_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 clock_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/clock` 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](http://exercism.io/tracks/python/tests).
+
+## Source
+
+Pairing session with Erin Drummond [https://twitter.com/ebdrummond](https://twitter.com/ebdrummond)
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

python/clock/clock.py

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+class Clock(object):
+    def __init__(self, hour, minute):
+        self.hour, self.minute = hour, minute
+
+    def __repr__(self):
+        return '<Clock {}:{}>'.format(str(self.hour).zfill(2), str(self.minute).zfill(2))
+
+    def __eq__(self, other):
+        return self.hour == other.hour and self.minute == other.minute
+
+    def change(self, minutes):
+        self.minute += minutes
+        while self.minute >= 60 or self.minute < 0:
+            if self.minute >= 60:
+                self.hour += 1
+                self.minute -= 60
+            elif self.minute < 0:
+                self.hour -= 1
+                self.minute += 60
+        self.hour = self.hour % 24
+
+    def __add__(self, minutes):
+        return self.change(minutes)
+
+    def __sub__(self, minutes):
+        return self.change(-minutes)

python/clock/clock_test.py

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+import unittest
+
+from clock import Clock
+
+
+# Tests adapted from `problem-specifications//canonical-data.json` @ v2.4.0
+
+class ClockTest(unittest.TestCase):
+    # Test creating a new clock with an initial time.
+    def test_on_the_hour(self):
+        self.assertEqual(str(Clock(8, 0)), '08:00')
+
+    def test_past_the_hour(self):
+        self.assertEqual(str(Clock(11, 9)), '11:09')
+
+    def test_midnight_is_zero_hours(self):
+        self.assertEqual(str(Clock(24, 0)), '00:00')
+
+    def test_hour_rolls_over(self):
+        self.assertEqual(str(Clock(25, 0)), '01:00')
+
+    def test_hour_rolls_over_continuously(self):
+        self.assertEqual(str(Clock(100, 0)), '04:00')
+
+    def test_sixty_minutes_is_next_hour(self):
+        self.assertEqual(str(Clock(1, 60)), '02:00')
+
+    def test_minutes_roll_over(self):
+        self.assertEqual(str(Clock(0, 160)), '02:40')
+
+    def test_minutes_roll_over_continuously(self):
+        self.assertEqual(str(Clock(0, 1723)), '04:43')
+
+    def test_hour_and_minutes_roll_over(self):
+        self.assertEqual(str(Clock(25, 160)), '03:40')
+
+    def test_hour_and_minutes_roll_over_continuously(self):
+        self.assertEqual(str(Clock(201, 3001)), '11:01')
+
+    def test_hour_and_minutes_roll_over_to_exactly_midnight(self):
+        self.assertEqual(str(Clock(72, 8640)), '00:00')
+
+    def test_negative_hour(self):
+        self.assertEqual(str(Clock(-1, 15)), '23:15')
+
+    def test_negative_hour_rolls_over(self):
+        self.assertEqual(str(Clock(-25, 0)), '23:00')
+
+    def test_negative_hour_rolls_over_continuously(self):
+        self.assertEqual(str(Clock(-91, 0)), '05:00')
+
+    def test_negative_minutes(self):
+        self.assertEqual(str(Clock(1, -40)), '00:20')
+
+    def test_negative_minutes_roll_over(self):
+        self.assertEqual(str(Clock(1, -160)), '22:20')
+
+    def test_negative_minutes_roll_over_continuously(self):
+        self.assertEqual(str(Clock(1, -4820)), '16:40')
+
+    def test_negative_sixty_minutes_is_previous_hour(self):
+        self.assertEqual(str(Clock(2, -60)), '01:00')
+
+    def test_negative_hour_and_minutes_both_roll_over(self):
+        self.assertEqual(str(Clock(-25, -160)), '20:20')
+
+    def test_negative_hour_and_minutes_both_roll_over_continuously(self):
+        self.assertEqual(str(Clock(-121, -5810)), '22:10')
+
+    # Test adding and subtracting minutes.
+    def test_add_minutes(self):
+        self.assertEqual(str(Clock(10, 0) + 3), '10:03')
+
+    def test_add_no_minutes(self):
+        self.assertEqual(str(Clock(6, 41) + 0), '06:41')
+
+    def test_add_to_next_hour(self):
+        self.assertEqual(str(Clock(0, 45) + 40), '01:25')
+
+    def test_add_more_than_one_hour(self):
+        self.assertEqual(str(Clock(10, 0) + 61), '11:01')
+
+    def test_add_more_than_two_hours_with_carry(self):
+        self.assertEqual(str(Clock(0, 45) + 160), '03:25')
+
+    def test_add_across_midnight(self):
+        self.assertEqual(str(Clock(23, 59) + 2), '00:01')
+
+    def test_add_more_than_one_day(self):
+        self.assertEqual(str(Clock(5, 32) + 1500), '06:32')
+
+    def test_add_more_than_two_days(self):
+        self.assertEqual(str(Clock(1, 1) + 3500), '11:21')
+
+    def test_subtract_minutes(self):
+        self.assertEqual(str(Clock(10, 3) - 3), '10:00')
+
+    def test_subtract_to_previous_hour(self):
+        self.assertEqual(str(Clock(10, 3) - 30), '09:33')
+
+    def test_subtract_more_than_an_hour(self):
+        self.assertEqual(str(Clock(10, 3) - 70), '08:53')
+
+    def test_subtract_across_midnight(self):
+        self.assertEqual(str(Clock(0, 3) - 4), '23:59')
+
+    def test_subtract_more_than_two_hours(self):
+        self.assertEqual(str(Clock(0, 0) - 160), '21:20')
+
+    def test_subtract_more_than_two_hours_with_borrow(self):
+        self.assertEqual(str(Clock(6, 15) - 160), '03:35')
+
+    def test_subtract_more_than_one_day(self):
+        self.assertEqual(str(Clock(5, 32) - 1500), '04:32')
+
+    def test_subtract_more_than_two_days(self):
+        self.assertEqual(str(Clock(2, 20) - 3000), '00:20')
+
+    # Construct two separate clocks, set times, test if they are equal.
+    def test_clocks_with_same_time(self):
+        self.assertEqual(Clock(15, 37), Clock(15, 37))
+
+    def test_clocks_a_minute_apart(self):
+        self.assertNotEqual(Clock(15, 36), Clock(15, 37))
+
+    def test_clocks_an_hour_apart(self):
+        self.assertNotEqual(Clock(14, 37), Clock(15, 37))
+
+    def test_clocks_with_hour_overflow(self):
+        self.assertEqual(Clock(10, 37), Clock(34, 37))
+
+    def test_clocks_with_hour_overflow_by_several_days(self):
+        self.assertEqual(Clock(3, 11), Clock(99, 11))
+
+    def test_clocks_with_negative_hour(self):
+        self.assertEqual(Clock(22, 40), Clock(-2, 40))
+
+    def test_clocks_with_negative_hour_that_wraps(self):
+        self.assertEqual(Clock(17, 3), Clock(-31, 3))
+
+    def test_clocks_with_negative_hour_that_wraps_multiple_times(self):
+        self.assertEqual(Clock(13, 49), Clock(-83, 49))
+
+    def test_clocks_with_minute_overflow(self):
+        self.assertEqual(Clock(0, 1), Clock(0, 1441))
+
+    def test_clocks_with_minute_overflow_by_several_days(self):
+        self.assertEqual(Clock(2, 2), Clock(2, 4322))
+
+    def test_clocks_with_negative_minute(self):
+        self.assertEqual(Clock(2, 40), Clock(3, -20))
+
+    def test_clocks_with_negative_minute_that_wraps(self):
+        self.assertEqual(Clock(4, 10), Clock(5, -1490))
+
+    def test_clocks_with_negative_minute_that_wraps_multiple_times(self):
+        self.assertEqual(Clock(6, 15), Clock(6, -4305))
+
+    def test_clocks_with_negative_hours_and_minutes(self):
+        self.assertEqual(Clock(7, 32), Clock(-12, -268))
+
+    def test_clocks_with_negative_hours_and_minutes_that_wrap(self):
+        self.assertEqual(Clock(18, 7), Clock(-54, -11513))
+
+    def test_full_clock_and_zeroed_clock(self):
+        self.assertEqual(Clock(24, 0), Clock(0, 0))
+
+
+if __name__ == '__main__':
+    unittest.main()