The classical introductory exercise. Just say "Hello, World!".
"Hello, World!" is the traditional first program for beginning programming in a new language or environment.
The objectives are simple:
If everything goes well, you will be ready to fetch your first real exercise.
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):
py.test hello_world_test.py
pytest hello_world_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 hello_world_test.py
pytest
options-v
: enable verbose output-x
: stop running tests on first failure--ff
: run failures from previous test before running other test casesFor 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/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.
This is an exercise to introduce users to using Exercism http://en.wikipedia.org/wiki/%22Hello,_world!%22_program
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
import unittest
import hello_world
# Tests adapted from `problem-specifications//canonical-data.json` @ v1.1.0
class HelloWorldTest(unittest.TestCase):
def test_say_hi(self):
self.assertEqual(hello_world.hello(), "Hello, World!")
if __name__ == "__main__":
unittest.main()
def hello():
return "Hello, World!"
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.
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