Calculate the moment when someone has lived for 10^9 seconds.
A gigasecond is 10^9 (1,000,000,000) seconds.
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 the appropriate command below (why they are different):
Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version):
python -m pytest gigasecond_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 the help page.
Chapter 9 in Chris Pine's online Learn to Program tutorial. http://pine.fm/LearnToProgram/?Chapter=09
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
import unittest from datetime import datetime from gigasecond import add_gigasecond # Tests adapted from `problem-specifications//canonical-data.json` @ v1.1.0 class GigasecondTest(unittest.TestCase): def test_date_only_specification_of_time(self): self.assertEqual( add_gigasecond(datetime(2011, 4, 25)), datetime(2043, 1, 1, 1, 46, 40)) def test_another_date_only_specification_of_time(self): self.assertEqual( add_gigasecond(datetime(1977, 6, 13)), datetime(2009, 2, 19, 1, 46, 40)) def test_one_more_date_only_specification_of_time(self): self.assertEqual( add_gigasecond(datetime(1959, 7, 19)), datetime(1991, 3, 27, 1, 46, 40)) def test_full_time_specified(self): self.assertEqual( add_gigasecond(datetime(2015, 1, 24, 22, 0, 0)), datetime(2046, 10, 2, 23, 46, 40)) def test_full_time_with_day_roll_over(self): self.assertEqual( add_gigasecond(datetime(2015, 1, 24, 23, 59, 59)), datetime(2046, 10, 3, 1, 46, 39)) def test_yourself(self): # customize this to test your birthday and find your gigasecond date: your_birthday = datetime(1970, 1, 1) your_gigasecond = datetime(2001, 9, 9, 1, 46, 40) self.assertEqual(add_gigasecond(your_birthday), your_gigasecond) if __name__ == '__main__': unittest.main()
from datetime import timedelta def add_gigasecond(birth_date): return birth_date + timedelta(0, 1e9)
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.