sashaflores / credit_risk_analysis

This project aims to build and evaluate several machine-learning models to predict credit risk using free data from LendingClub.

Risky Business

In this project, you will build and evaluate several machine-learning models to predict credit risk using free data from LendingClub. Credit risk is an inherently imbalanced classification problem (the number of good loans is much larger than the number of at-risk loans), so you will need to employ different techniques for training and evaluating models with imbalanced classes. You will use the imbalanced-learn and Scikit-learn libraries to build and evaluate models using the two following techniques:

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Files

Resampling Starter Notebook

Ensemble Starter Notebook

Lending Club Loans Data

Evaluation Report

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Resampling

You will use the imbalanced learn library to resample the LendingClub data and build and evaluate logistic regression classifiers using the resampled data.

You will:

1. Load the Lending Club data, split the data into training and testing sets.

    from sklearn.model_selection import train_test_split
   
    X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=1)
   

2. Scale the features data.

    from sklearn.preprocessing import StandardScaler
    scaler = StandardScaler()
   

3. Oversample the data using the Naive Random Oversampler algorithms.

    from imblearn.over_sampling import RandomOverSampler
   
    ros = RandomOverSampler(random_state=1)
    X_resampled, y_resampled = ros.fit_resample(X_train_scaled, y_train)
   

4. Oversample the data using the SMOTE algorithms.

    from imblearn.over_sampling import SMOTE
   
    X_resampled, y_resampled = SMOTE(random_state=1, sampling_strategy=1.0).fit_resample(X_train_scaled, y_train)
   

5. Undersample the data using the Cluster Centroids algorithm.

    from imblearn.under_sampling import ClusterCentroids
   
    cc = ClusterCentroids(random_state=1)
    X_resampled, y_resampled = cc.fit_resample(X_train_scaled, y_train)
   

6. Over- and under-sample using a combination SMOTEENN algorithm.

    X_resampled, y_resampled = SMOTE(random_state=1, sampling_strategy=1.0).fit_resample(X_train, y_train)
   

For each of the above, you will need to:

7. Train a logistic regression classifier from sklearn.linear_model using the resampled data.

    model = LogisticRegression(solver='lbfgs', random_state=1)
    model.fit(X_resampled, y_resampled)
   

8. Calculate the balanced accuracy score from sklearn.metrics.

    y_pred = model.predict(X_test_scaled)
    balanced_accuracy_score(y_test, y_pred)
   

9. Calculate the confusion matrix from sklearn.metrics.

   confusion_matrix(y_test, y_pred)
   

10. Print the imbalanced classification report from imblearn.metrics.

    Random Sampling

    

    Smote Over Sampling

    

    Under Sampling

    

    Combination Sampling

    

Ensemble Learning

In this section, you will train and compare two different ensemble classifiers to predict loan risk and evaluate each model. You will use the Balanced Random Forest Classifier and the Easy Ensemble Classifier. Refer to the documentation for each of these to read about the models and see examples of the code.

Be sure to complete the following steps for each model:

1. Load the Lending Club data, split the data into training and testing sets, and scale the features data.

    from sklearn.model_selection import train_test_split
   
    X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=1)
   

2. Train the model using the quarterly data from LendingClub provided in the Resource folder.

    from imblearn.ensemble import BalancedRandomForestClassifier
   
    model = BalancedRandomForestClassifier(n_estimators=100, random_state=1)
    model = model.fit(X_train_scaled, y_train)
   

3. Calculate the balanced accuracy score from sklearn.metrics.

    y_pred = model.predict(X_test_scaled)
    balanced_accuracy_score(y_test, y_pred)
   

4. Print the confusion matrix from sklearn.metrics.

5. Generate a classification report using the imbalanced_classification_report from imbalanced learn.

Balanced Random Forest Classifier

Easy Ensemble Classifier

6. For the balanced random forest classifier only, print the feature importance sorted in descending order (most important feature to least important) along with the feature score.

    importances = model.feature_importances_
    importances_sorted = sorted(zip(model.feature_importances_, X.columns), reverse=True)
   

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After running and evaluating the ML Models, you should now be able to answer the following:

Which model had the best balanced accuracy score?

Which model had the best recall score?

Which model had the best geometric mean score?

What are the top three features?

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Resources

Use the quarterly data from the LendingClub data that is provided in the Resources folder. Keep the file in the zipped format and use the starter code to read the file.

Refer to the imbalanced-learn and scikit-learn official documentation for help with training the models. Remember that these models all use the model->fit->predict API.

For the ensemble learners, use 100 estimators for both models.

Loan Data Analysis and Visualization using Lending Club Data Data Science Blog

Decision Trees and Random Forests Towards Data Science

Decision Trees and Random Forests Medium.com

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