Problem 4: Combine a Pipeline with GridSearchCV

Problem Description

Write a Python program that builds a Pipeline with a scaler and a LogisticRegression classifier, then uses GridSearchCV to tune the classifier's regularization strength (C parameter) within the pipeline.

Input

A labeled dataset and a small set of candidate C values.

Output

The best C value found and its Cross-Validation score.

Constraints

• At least 20 labeled examples.

Example Input

text
(A labeled dataset, C candidates: [0.1, 1, 10])

Example Output

text
Best parameters: {'classifier__C': 1}
Best score: 0.88

Concepts Covered

Pipeline, GridSearchCV, parameter naming with __ for pipeline steps.