Respuesta :
Answer:
In a pipeline with preprocessing steps and a final model, the `fit_transform` function will be called **exactly 3 times**.
Here's the breakdown:
1. **Each Preprocessing Step:** Each preprocessing step (except the last one) needs to learn parameters from the data (like mean and variance for scaling) before transforming new data. Therefore, `fit_transform` is called on each preprocessing step to achieve this combined functionality.
2. **Final Model:** The final model typically uses `fit` instead of `fit_transform` because it doesn't need to transform the data during training. It only learns from the preprocessed data passed by the pipeline.
So, even though `fit_transform` is a convenient function, it's called only on the individual preprocessing steps within the pipeline, not on the final model itself.
