# The predictions module

The `surprise.prediction_algorithms.predictions` module defines the `Prediction` named tuple and the `PredictionImpossible` exception.

class `surprise.prediction_algorithms.predictions.``Prediction`

  A named tuple for storing the results of a prediction.

  It’s wrapped in a class, but only for documentation and printing purposes.

  Parameters: | uid – The (raw) user id. See this note. iid – The (raw) item id. See this note. r_ui (float) – The true rating \(r_{ui}\). est (float) – The estimated rating \(\hat{r}_{ui}\). details (dict) – Stores additional details about the prediction that might be useful for later analysis.

exception `surprise.prediction_algorithms.predictions.``PredictionImpossible`

  Exception raised when a prediction is impossible.

  When raised, the estimation \(\hat{r}_{ui}\) is set to the global mean of all ratings \(\mu\).