# Hello World The classical introductory exercise. Just say "Hello, World!". ["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is the traditional first program for beginning programming in a new language or environment. The objectives are simple: - Write a function that returns the string "Hello, World!". - Run the test suite and make sure that it succeeds. - Submit your solution and check it at the website. If everything goes well, you will be ready to fetch your first real exercise. ## 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 `pytest hello_world_test.py` Alternatively, you can tell Python to run the pytest module: `python -m pytest hello_world_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/hello-world` 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](http://exercism.io/tracks/python/tests). ## Source This is an exercise to introduce users to using Exercism [http://en.wikipedia.org/wiki/%22Hello,_world!%22_program](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.