Surprise is a Python scikit for building and analyzing recommender systems that deal with explicit rating data.

Surprise was designed with the following purposes in mind:

The name SurPRISE (roughly :) ) stands for Simple Python RecommendatIon System Engine.

Please note that surprise does not support implicit ratings or content-based information.

Getting started, example

Here is a simple example showing how you can (down)load a dataset, split it for 5-fold cross-validation, and compute the MAE and RMSE of the SVD algorithm.

from surprise import SVD
from surprise import Dataset
from surprise.model_selection import cross_validate

# Load the movielens-100k dataset (download it if needed).
data = Dataset.load_builtin('ml-100k')

# Use the famous SVD algorithm.
algo = SVD()

# Run 5-fold cross-validation and print results.
cross_validate(algo, data, measures=['RMSE', 'MAE'], cv=5, verbose=True)


Evaluating RMSE, MAE of algorithm SVD on 5 split(s).

                  Fold 1  Fold 2  Fold 3  Fold 4  Fold 5  Mean    Std     
RMSE (testset)    0.9367  0.9355  0.9378  0.9377  0.9300  0.9355  0.0029  
MAE (testset)     0.7387  0.7371  0.7393  0.7397  0.7325  0.7375  0.0026  
Fit time          0.62    0.63    0.63    0.65    0.63    0.63    0.01    
Test time         0.11    0.11    0.14    0.14    0.14    0.13    0.02    

Surprise can do much more (e.g, GridSearchCV)! You’ll find more usage examples in the documentation .


Here are the average RMSE, MAE and total execution time of various algorithms (with their default parameters) on a 5-fold cross-validation procedure. The datasets are the Movielens 100k and 1M datasets. The folds are the same for all the algorithms. All experiments are run on a laptop with an intel i5 11th Gen 2.60GHz. The code for generating these tables can be found in the benchmark example.

Movielens 100k RMSE MAE Time
SVD 0.934 0.737 0:00:06
SVD++ (cache_ratings=False) 0.919 0.721 0:01:39
SVD++ (cache_ratings=True) 0.919 0.721 0:01:22
NMF 0.963 0.758 0:00:06
Slope One 0.946 0.743 0:00:09
k-NN 0.98 0.774 0:00:08
Centered k-NN 0.951 0.749 0:00:09
k-NN Baseline 0.931 0.733 0:00:13
Co-Clustering 0.963 0.753 0:00:06
Baseline 0.944 0.748 0:00:02
Random 1.518 1.219 0:00:01
Movielens 1M RMSE MAE Time
SVD 0.873 0.686 0:01:07
SVD++ (cache_ratings=False) 0.862 0.672 0:41:06
SVD++ (cache_ratings=True) 0.862 0.672 0:34:55
NMF 0.916 0.723 0:01:39
Slope One 0.907 0.715 0:02:31
k-NN 0.923 0.727 0:05:27
Centered k-NN 0.929 0.738 0:05:43
k-NN Baseline 0.895 0.706 0:05:55
Co-Clustering 0.915 0.717 0:00:31
Baseline 0.909 0.719 0:00:19
Random 1.504 1.206 0:00:19


With pip (you’ll need numpy, and a C compiler. Windows users might prefer using conda):

$ pip install numpy
$ pip install scikit-surprise

With conda:

$ conda install -c conda-forge scikit-surprise

For the latest version, you can also clone the repo and build the source (you’ll first need Cython and numpy):

$ pip install numpy cython
$ git clone https://github.com/NicolasHug/surprise.git
$ cd surprise
$ python setup.py install

License and reference

This project is licensed under the BSD 3-Clause license, so it can be used for pretty much everything, including commercial applications.

I’d love to know how Surprise is useful to you. Please don’t hesitate to open an issue and describe how you use it!

Please make sure to cite the paper if you use Surprise for your research:

  doi = {10.21105/joss.02174},
  url = {https://doi.org/10.21105/joss.02174},
  year = {2020},
  publisher = {The Open Journal},
  volume = {5},
  number = {52},
  pages = {2174},
  author = {Nicolas Hug},
  title = {Surprise: A Python library for recommender systems},
  journal = {Journal of Open Source Software}


The following persons have contributed to Surprise:

ashtou, Abhishek Bhatia, bobbyinfj, caoyi, Chieh-Han Chen, Raphael-Dayan, Олег Демиденко, Charles-Emmanuel Dias, dmamylin, Lauriane Ducasse, Marc Feger, franckjay, Lukas Galke, Tim Gates, Pierre-François Gimenez, Zachary Glassman, Jeff Hale, Nicolas Hug, Janniks, jyesawtellrickson, Doruk Kilitcioglu, Ravi Raju Krishna, lapidshay, Hengji Liu, Ravi Makhija, Maher Malaeb, Manoj K, James McNeilis, Naturale0, nju-luke, Pierre-Louis Pécheux, Jay Qi, Lucas Rebscher, Craig Rodrigues, Skywhat, Hercules Smith, David Stevens, Vesna Tanko, TrWestdoor, Victor Wang, Mike Lee Williams, Jay Wong, Chenchen Xu, YaoZh1918.

Thanks a lot :) !

Development Status

Starting from version 1.1.0 (September 2019), I will only maintain the package, provide bugfixes, and perhaps sometimes perf improvements. I have less time to dedicate to it now, so I’m unabe to consider new features.

For bugs, issues or questions about Surprise, please avoid sending me emails; I will most likely not be able to answer). Please use the GitHub project page instead, so that others can also benefit from it.