Source code for surprise.prediction_algorithms.predictions

The :mod:`surprise.prediction_algorithms.predictions` module defines the
:class:`Prediction` named tuple and the :class:`PredictionImpossible`

from collections import namedtuple

[docs]class PredictionImpossible(Exception): r"""Exception raised when a prediction is impossible. When raised, the estimation :math:`\hat{r}_{ui}` is set to the global mean of all ratings :math:`\mu`. """ pass
[docs]class Prediction(namedtuple("Prediction", ["uid", "iid", "r_ui", "est", "details"])): """A named tuple for storing the results of a prediction. It's wrapped in a class, but only for documentation and printing purposes. Args: uid: The (raw) user id. See :ref:`this note<raw_inner_note>`. iid: The (raw) item id. See :ref:`this note<raw_inner_note>`. r_ui(float): The true rating :math:`r_{ui}`. est(float): The estimated rating :math:`\\hat{r}_{ui}`. details (dict): Stores additional details about the prediction that might be useful for later analysis. """ __slots__ = () # for memory saving purpose. def __str__(self): s = f"user: {self.uid:<10} " s += f"item: {self.iid:<10} " if self.r_ui is not None: s += f"r_ui = {self.r_ui:1.2f} " else: s += "r_ui = None " s += f"est = {self.est:1.2f} " s += str(self.details) return s