Pipelines

~12 mincode completion

Write build_and_score(X_train, y_train, X_test, y_test) that builds a plus pipeline, fits it on the training data, and returns its accuracy on the test data as a float.

Pass random_state=0 to so the result is reproducible.

Examples

A cleanly separable problem is classified perfectly

Input
build_and_score([[0], [1], [2], [8], [9], [10]], [0, 0, 0, 1, 1, 1], [[0.5], [9.5]], [0, 1])
Output
1

Two features, still separable, still perfect

Input
build_and_score([[0, 0], [1, 1], [9, 9], [10, 10]], [0, 0, 1, 1], [[0.5, 0.5], [9.5, 9.5]], [0, 1])
Output
1

Hints

Hint 1

Work directly with the arguments X_train, y_train, X_test, y_test and return the result rather than printing it.

Hint 2

Watch for this: scaled outside the pipeline.

Requirements

  • Return Accuracy on the test set, as a float.

Constraints

  • Allowed library: NumPy only

  • Time limit: 200 ms, Memory: 64 MB

Where this shows up

~12 min

7 employers weight this skill

2 health and bio companies, 2 quant funds, 2 enterprise vendors, 1 AI product company. Top match scores 43.

Python
import numpy as np
from sklearn.pipeline import Pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LogisticRegression

def build_and_score(X_train, y_train, X_test, y_test):
    """
    Build a scaler + classifier pipeline, fit it, and score it.

    Args:
        X_train, y_train: training data
        X_test, y_test: held-out data

    Returns:
        Accuracy on the test set, as a float.
    """
    # YOUR CODE HERE
    pass

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