2-fer is short for two for one. One for you and one for me.
"One for X, one for me."
When X is a name or "you".
If the given name is "Alice", the result should be "One for Alice, one for me." If no name is given, the result should be "One for you, one for me."
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 two_fer_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.
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
import unittest from two_fer import two_fer # Tests adapted from `problem-specifications//canonical-data.json` @ v1.2.0 class TwoFerTest(unittest.TestCase): def test_no_name_given(self): self.assertEqual(two_fer(), 'One for you, one for me.') def test_a_name_given(self): self.assertEqual(two_fer("Alice"), "One for Alice, one for me.") def test_another_name_given(self): self.assertEqual(two_fer("Bob"), "One for Bob, one for me.") if __name__ == '__main__': unittest.main()
def two_fer(name="you"): return "One for " + name + ", one for me."
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.