Python: clock

python/clock/.exercism/metadata.json

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+{"track":"python","exercise":"clock","id":"ba856df2676641fd8ad5587c6a71ad92","url":"https://exercism.io/my/solutions/ba856df2676641fd8ad5587c6a71ad92","handle":"DmitryKokorin","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 `pytest clock_test.py`
+
+Alternatively, you can tell Python to run the pytest module:
+`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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+HOURS_IN_DAY = 24
+MINUTES_IN_HOUR = 60
+MINUTES_IN_DAY = HOURS_IN_DAY*MINUTES_IN_HOUR
+
+
+class Clock:
+    def __init__(self, hour=0, minute=0):
+        self.minutes = (MINUTES_IN_HOUR*hour + minute) % MINUTES_IN_DAY
+
+    def __repr__(self):
+        hours = self.minutes // MINUTES_IN_HOUR
+        minutes = self.minutes % MINUTES_IN_HOUR
+        return f'{hours:02}:{minutes:02}'
+
+    def __eq__(self, other):
+        return self.minutes == other.minutes
+
+    def __add__(self, minutes):
+        clock = Clock()
+        clock.minutes = (self.minutes + minutes) % MINUTES_IN_DAY
+        return clock
+
+    def __sub__(self, minutes):
+        return self.__add__(-minutes)

python/clock/clock_test.py

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+import unittest
+
+from clock import Clock
+
+# Tests adapted from `problem-specifications//canonical-data.json`
+
+
+class ClockTest(unittest.TestCase):
+    # Create 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")
+
+    # Add 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_1500_min_25_hrs(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")
+
+    # Subtract Minutes
+    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_1500_min_25_hrs(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")
+
+    # Compare Two Clocks For Equality
+    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()