Martin

@NicolasHug How can we enable tests on this base branch so that I can see which tests fail?

What is the best way to run the tests locally without having to do `python test_name.py` for each test?

I have corrected the tests so that they now work on my computer running `pytest`. Unfortunately, I don't have time to make new tests to check the features option.

I have been working on other projects in the mean time but this branch should work without issues. However, I would recommend using my factorization-machines branch as it should contain...

If you want to add user/item features to a factorization algorithm, you should take a look at [factorization machines](https://cseweb.ucsd.edu/classes/fa17/cse291-b/reading/Rendle2010FM.pdf). I have a working implementation at [factorization_machines.py](https://github.com/martincousi/Surprise/blob/sample_weight/surprise/prediction_algorithms/factorization_machines.py). Note that this the...

So, sample weights could be passed by the user to the `trainset` object or computed in the `trainset` object according to one of many options. This option might need to...

I have added three new factorization machine algos. They are many more possible but most of them can be accomplished by using the features. Additional ones could also be conceived...