We use [pytest][pytest: Getting Started Guide] as our website test runner.

You will need to install `pytest` on your development machine if you want to run tests for the Python track locally.

You should also install the following `pytest` plugins:

- [pytest-cache][pytest-cache]

- [pytest-subtests][pytest-subtests]

Extended information can be found in our website [Python testing guide][Python track tests page].

To run the included tests, navigate to the folder where the exercise is stored using `cd` in your terminal (_replace `{exercise-folder-location}` below with your path_).

Test files usually end in `_test.py`, and are the same tests that run on the website when a solution is uploaded.

Linux/MacOS

$ cd {path/to/exercise-folder-location}

Windows

<br>

Next, run the `pytest` command in your terminal, replacing `{exercise_test.py}` with the name of the test file:

Linux/MacOS

$ python3 -m pytest -o markers=task {exercise_test.py}

==================== 7 passed in 0.08s ====================

Windows

- `-o` : override default `pytest.ini` (_you can use this to avoid marker warnings_)

- `-v` : enable verbose output.

- `-x` : stop running tests on first failure.

- `--ff` : run failures from previous test before running other test cases.

For additional options, use `python3 -m pytest -h` or `py -m pytest -h`.

If you do not use `pytest -o markers=task` when invoking `pytest`, you might receive a `PytestUnknownMarkWarning` for tests that use our new syntax:

PytestUnknownMarkWarning: Unknown pytest.mark.task - is this a typo? You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/stable/mark.html

To avoid typing `pytest -o markers=task` for every test you run, you can use a `pytest.ini` configuration file.

We have made one that can be downloaded from the top level of the Python track directory: [pytest.ini][pytest.ini].

You can also create your own `pytest.ini` file with the following content:

markers =

task: A concept exercise task.

Placing the `pytest.ini` file in the _root_ or _working_ directory for your Python track exercises will register the marks and stop the warnings.

More information on pytest marks can be found in the `pytest` documentation on [marking test functions][pytest: marking test functions with attributes] and the `pytest` documentation on [working with custom markers][pytest: working with custom markers].

Information on customizing pytest configurations can be found in the `pytest` documentation on [configuration file formats][pytest: configuration file formats].

Many IDEs and code editors have built-in support for using `pytest` and other code quality tools.

Some community-sourced options can be found on our [Python track tools page][Python track tools page].

[Pytest: Getting Started Guide]: https://docs.pytest.org/en/latest/getting-started.html

[Python track tools page]: https://exercism.org/docs/tracks/python/tools

[Python track tests page]: https://exercism.org/docs/tracks/python/tests

[pytest-cache]:http://pythonhosted.org/pytest-cache/

[pytest-subtests]:https://github.com/pytest-dev/pytest-subtests

[pytest.ini]: https://github.com/exercism/python/blob/main/pytest.ini

[pytest: configuration file formats]: https://docs.pytest.org/en/6.2.x/customize.html#configuration-file-formats

[pytest: marking test functions with attributes]: https://docs.pytest.org/en/6.2.x/mark.html#raising-errors-on-unknown-marks

[pytest: working with custom markers]: https://docs.pytest.org/en/6.2.x/example/markers.html#working-with-custom-markers

You can submit your solution using the `exercism submit black_jack.py` command.

This command will upload your solution to the Exercism website and print the solution page's URL.

It's possible to submit an incomplete solution which allows you to:

- See how others have completed the exercise

- Request help from a mentor

If you'd like help solving the exercise, check the following pages:

- The [Python track's documentation](https://exercism.org/docs/tracks/python)

- The [Python track's programming category on the forum](https://forum.exercism.org/c/programming/python)

- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)

- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)

Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.

Below are some resources for getting help if you run into trouble:

- [The PSF](https://www.python.org) hosts Python downloads, documentation, and community resources.

- [The Exercism Community on Discord](https://exercism.org/r/discord)

- [Python Community on Discord](https://pythondiscord.com/) is a very helpful and active community.

- [/r/learnpython/](https://www.reddit.com/r/learnpython/) is a subreddit designed for Python learners.

- [#python on Libera.chat](https://www.python.org/community/irc/) this is where the core developers for the language hang out and get work done.

- [Python Community Forums](https://discuss.python.org/)

- [Free Code Camp Community Forums](https://forum.freecodecamp.org/)

- [CodeNewbie Community Help Tag](https://community.codenewbie.org/t/help)

- [Pythontutor](http://pythontutor.com/) for stepping through small code snippets visually.

Additionally, [StackOverflow](http://stackoverflow.com/questions/tagged/python) is a good spot to search for your problem/question to see if it has been answered already.

If not - you can always [ask](https://stackoverflow.com/help/how-to-ask) or [answer](https://stackoverflow.com/help/how-to-answer) someone else's question.

[The Python comparisons tutorial][python comparisons tutorial] and [Python comparisons examples][python comparisons examples] are a great introduction covering the content of this exercise.

- You can use the equality comparison operator `==` to determine if a card is an ace card: `card == 'A'`.

- You can use the containment operator `in` to determine if a substring is contained inside a string: `'Q' in 'KJQ'`.

- You can use the [`int` constructor][int constructor] to convert a `str` of an `int` to an `int`: `int('13')`.

- Once you have defined the `value_of_card` function, you can call it from other functions.

- You can use the value comparison operators `>` and `<` to determine if specific cards are _greater than_ or _less than_ a given value: `3 < 12`.

- You can use the equality comparison operator `==` to determine if two values are equal to one another.

- Once you have defined the `value_of_card` function, you can call it from other functions.

- You can use the order comparison operator `>` to decide the appropriate course of action here.

- Remember, you can use the [`if`/`elif`/`else` syntax][if syntax] to handle different combinations of cards.

- You can chain BOTH comparison operators and boolean operators _arbitrarily_: `y < z < x` or `(y or z) and (x or z)`

- You can reuse the already implemented `value_of_card` function.

- You can reuse the already implemented `value_of_card` function.

- You can handle the `A` case (when at least one of the cards in an ace) separately.

- An `A` scored at 11 will never allow doubling down if there are two cards in the hand.

- Given the first point, you _should_ be able to reuse the already implemented `value_of_card` function.

- You can chain comparison operators _arbitrarily_: `y < z < x`.

- You can use the [conditional expression][conditional expression] (_sometimes called a "ternary operator"_)

to shorten simple `if`/`else` statements: `13 if letter == 'M' else 3`.

[conditional expression]: https://docs.python.org/3/reference/expressions.html#conditional-expressions

[if syntax]: https://docs.python.org/3/tutorial/controlflow.html#if-statements

[int constructor]: https://docs.python.org/3/library/functions.html#int

[python comparisons examples]: https://www.tutorialspoint.com/python/comparison_operators_example.htm

[python comparisons tutorial]: https://docs.python.org/3/reference/expressions.html#comparisons