# Grade School

Given students' names along with the grade that they are in, create a roster
for the school.

In the end, you should be able to:

- Add a student's name to the roster for a grade
  - "Add Jim to grade 2."
  - "OK."
- Get a list of all students enrolled in a grade
  - "Which students are in grade 2?"
  - "We've only got Jim just now."
- Get a sorted list of all students in all grades.  Grades should sort
  as 1, 2, 3, etc., and students within a grade should be sorted
  alphabetically by name.
  - "Who all is enrolled in school right now?"
  - "Grade 1: Anna, Barb, and Charlie. Grade 2: Alex, Peter, and Zoe.
    Grade 3…"

Note that all our students only have one name.  (It's a small town, what
do you want?)

## For bonus points

Did you get the tests passing and the code clean? If you want to, these
are some additional things you could try:

- If you're working in a language with mutable data structures and your
  implementation allows outside code to mutate the school's internal DB
  directly, see if you can prevent this. Feel free to introduce additional
  tests.

Then please share your thoughts in a comment on the submission. Did this
experiment make the code better? Worse? Did you learn anything from it?

## 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 the appropriate command below ([why they are different](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):

- Python 2.7: `py.test grade_school_test.py`
- Python 3.3+: `pytest grade_school_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 grade_school_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/grade-school` 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 the [help page](http://exercism.io/languages/python).

## Source

A pairing session with Phil Battos at gSchool [http://gschool.it](http://gschool.it)

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.