Two-fer or 2-fer is short for two for one. One for you and one for me.
Given a name, return a string with the message:
One for X, one for me.
Where X is the given name.
However, if the name is missing, return the string:
One for you, one for me.
Here are some examples:
| Name | String to return |
|---|---|
| Alice | One for Alice, one for me. |
| Bob | One for Bob, one for me. |
| One for you, one for me. | |
| Zaphod | One for Zaphod, 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):
- Python 2.7:
py.test two_fer_test.py - Python 3.4+:
pytest two_fer_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 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 $EXERCISM_WORKSPACE/python/two-fer 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.
exercism/problem-specifications#757
It's possible to submit an incomplete solution so you can see how others have completed the exercise.