mrec is a Python package developed at Mendeley to support recommender systems development and evaluation. The package currently focuses on item similarity and other methods that work well on implicit feedback, and on experimental evaluation.

Why another package when there are already some really good software projects implementing recommender systems?

mrec tries to fill two small gaps in the current landscape, firstly by supplying simple tools for consistent and reproducible evaluation, and secondly by offering examples of how to use IPython.parallel to run the same code either on the cores of a single machine or on a cluster. The combination of IPython and scientific Python libraries is very powerful, but there are still rather few examples around that show how to get it to work in practice.

Highlights:

• a (relatively) efficient implementation of the SLIM item similarity method¹.
• an implementation of Hu, Koren & Volinsky's WRMF weighted matrix factorization for implicit feedback².
• a matrix factorization model that optimizes the Weighted Approximately Ranked Pairwise (WARP) ranking loss³.
• a hybrid model optimizing the WARP loss for a ranking based jointly on a user-item matrix and on content features for each item.
• utilities to train models and make recommendations in parallel using IPython.
• utilities to prepare datasets and compute quality metrics.

Documentation for mrec can be found at http://mendeley.github.io/mrec.

The source code is available at https://github.com/mendeley/mrec.

mrec implements the SLIM recommender described in⁴. Please cite this paper if you use mrec in your research.

To use mrec in your Python project:

1. Set up a virtualenv for your project... or don't.
2. Run pip install mrec

To set up the project on your own development machine, follow these steps.

To install the dependencies:

1. Install Cython, Numpy and Scipy. This is the difficult step. On Windows or OS X you could install one of the Scipy distributions. On Linuxes you could install libblas, liblapack, gfortran from your OS package manager, then run pip install cython numpy scipy.
2. Run python setup.py install to obtain the other Python dependencies.

To run the tests:

• Run py.test

For more specific project build instructions, please see the .travis.yml config file at the top of this Git repo, which specifies how Travis CI auto-builds and tests our project.

If you have fixed a bug or added a neat new feature, feel free to submit a pull request to us on GitHub.