Given a number, find the sum of all the unique multiples of particular numbers up to but not including that number.
If we list all the natural numbers below 20 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12, 15, and 18.
The sum of these multiples is 78.
You can make the following assumptions about the inputs to the
sum_of_multiples function:
- All input numbers are non-negative
ints, i.e. natural numbers including zero. - A list of factors must be given, and its elements are unique and sorted in ascending order.
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 pytest sum_of_multiples_test.py
Alternatively, you can tell Python to run the pytest module:
python -m pytest sum_of_multiples_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/sum-of-multiples 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.
A variation on Problem 1 at Project Euler http://projecteuler.net/problem=1
It's possible to submit an incomplete solution so you can see how others have completed the exercise.