Get the sources


git clone


git clone


The dependencies of nuancier are listed in the file requirements.txt at the top level of the sources.

Run nuancier for development

Create the database scheme:


Run the server:


You should be able to access the server at http://localhost:5000

Every time you save a file, the project will be automatically restarted so you can see your change immediatly.


You may want to adjust the values in nuancier/ especially the ADMIN_GROUP if you are not part of the default one. See Configuration for more information about the configuration.

Coding standards

We are trying to make the code PEP8-compliant. There is a pep8 tool that can automatically check your source.

We are also inspecting the code using pylint and aim,of course, for a 10/10 code (but it is an asymptotic goal).


both pep8 and pylint are available in Fedora via yum:

yum install python-pep8 pylint

Send patch

The easiest way to work on nuancier is to make your own branch in git, make your changes to this branch, commit whenever you want, rebase on master whenever you need and when you are done, send the patch either by email or via the github pull-request mechanism.

The workflow would therefore be something like:

git branch <my_shiny_feature>
git checkout <my_shiny_feature>
git commit file1 file2
<more work>
git commit file3 file4
git checkout master
git pull
git checkout <my_shiny_feature>
git rebase master
git format-patch -2

This will create two patch files that you can send by email to submit in the trac.


Nuancier has a number of unit-tests providing at the moment a full coverage of the backend library (nuancier.lib).

We aim at having a full (100%) coverage of the whole code (including the Flask application) and of course a smart coverage as in we want to check that the functions work the way we want but also that they fail when we expect it and the way we expect it.

Tests checking that function are failing when/how we want are as important as tests checking they work the way they are intended to., located at the top of the sources, helps to run the unit-tests of the project with coverage information using python-nose.


You can specify additional arguments to the nose command used in this script by just passing arguments to the script.

For example you can specify the -x / --stop argument: Stop running tests after the first error or failure by just doing

./ --stop

Unit-test files(located under tests/) can be can be invoked individually, allowing easier debugging of the tests. For example:

python tests/

Similarly as for nose you can also ask that the unit-test stop at the first error or failure. For example, the command could be:

python -m unittest -f -v tests.test_model


In order to have coverage information you might have to install python-coverage

yum install python-coverage

Database changes

We try to make the database schema as stable as possible, however once in a while we need to change it to add new features or information.

When database changes are made, they should have the corresponding change handled via alembic.

See the alembic tutorial for complete information on how to make a revision to the database schema.

The basic idea is to create a revision using (in the top folder):

alembic revision -m "<description of the change>"

Then edit the file generated in alembic/versions/ to add the correct command for upgrade and downgrade (for example: op.add_column, op.drop_column, op.create_table, op.drop_table).