├── CreditScoringToolkit.py
├── requirements-dev.txt
├── pytest.ini
├── images
├── score_kde.png
├── event_range_5.png
├── roc_auc_curve.png
├── event_range_10.png
├── score_histogram.png
├── scoring_method.png
├── Usage Example_22_0.png
├── Usage Example_22_1.png
├── Usage Example_24_1.png
├── Usage Example_24_3.png
└── feature_importance.png
├── reports
├── iv_report.png
├── roc_curve.png
├── score_kde.png
├── event_rate_5.png
├── event_rate_10.png
└── score_histogram.png
├── requirements.txt
├── CHANGELOG.md
├── woe_credit_scoring
├── __init__.py
├── reporter.py
├── base.py
├── encoder.py
├── scoring.py
├── normalizer.py
├── binning.py
└── autocreditscoring.py
├── pyproject.toml
├── tests
├── unit
│ ├── test_normalizer.py
│ ├── test_feature_selectors.py
│ └── test_encoder.py
└── integration
│ ├── test_autocreditscoring_pipeline.py
│ └── test_manual_pipeline.py
├── .gitignore
├── README.md
└── LICENSE
/CreditScoringToolkit.py:
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1 | from woe_credit_scoring import *
2 |
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/requirements-dev.txt:
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1 | pytest
2 | pandas
3 | scikit-learn
4 |
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/pytest.ini:
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1 | [pytest]
2 | minversion = 6.0
3 | testpaths = tests
4 |
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/images/score_kde.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/score_kde.png
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/reports/iv_report.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/iv_report.png
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/reports/roc_curve.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/roc_curve.png
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/reports/score_kde.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/score_kde.png
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/images/event_range_5.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/event_range_5.png
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/images/roc_auc_curve.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/roc_auc_curve.png
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/reports/event_rate_5.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/event_rate_5.png
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/images/event_range_10.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/event_range_10.png
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/images/score_histogram.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/score_histogram.png
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/images/scoring_method.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/scoring_method.png
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/reports/event_rate_10.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/event_rate_10.png
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/images/Usage Example_22_0.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/Usage Example_22_0.png
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/images/Usage Example_22_1.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/Usage Example_22_1.png
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/images/Usage Example_24_1.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/Usage Example_24_1.png
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/images/Usage Example_24_3.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/Usage Example_24_3.png
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/images/feature_importance.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/images/feature_importance.png
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/reports/score_histogram.png:
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https://raw.githubusercontent.com/JGFuentesC/woe_credit_scoring/HEAD/reports/score_histogram.png
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/requirements.txt:
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1 | numpy>=1.21.0
2 | pandas>=1.3.0
3 | scikit-learn>=1.0.0
4 | seaborn>=0.11.0
5 | matplotlib>=3.4.0
6 | scipy>=1.7.0
7 | ipykernel>=6.0.0
8 |
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/CHANGELOG.md:
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1 | # Changelog
2 |
3 | ## [2.0.4] - 2025-12-20
4 |
5 | ### Features
6 | - Refactored the project into a multi-file package structure for better organization and maintainability.
7 | - Added a comprehensive suite of unit and integration tests to ensure code quality and stability.
8 |
9 | ### Fixes
10 | - Resolved several minor bugs identified during the refactoring and testing process.
11 |
12 | ### Chore
13 | - Added development dependencies and pytest configuration for a formal testing process.
14 |
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/woe_credit_scoring/__init__.py:
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1 | # woe_credit_scoring/__init__.py
2 |
3 | from .normalizer import DiscreteNormalizer
4 | from .reporter import frequency_table
5 | from .base import WoeBaseFeatureSelector
6 | from .binning import Discretizer, WoeContinuousFeatureSelector, WoeDiscreteFeatureSelector, IVCalculator
7 | from .encoder import WoeEncoder
8 | from .scoring import CreditScoring
9 | from .autocreditscoring import AutoCreditScoring
10 |
11 |
12 | __all__ = [
13 | "DiscreteNormalizer", "frequency_table", "WoeBaseFeatureSelector",
14 | "Discretizer", "WoeEncoder", "WoeContinuousFeatureSelector", "WoeDiscreteFeatureSelector",
15 | "CreditScoring", "AutoCreditScoring", "IVCalculator"
16 | ]
17 |
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/pyproject.toml:
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1 | [build-system]
2 | requires = ["setuptools>=61.0"]
3 | build-backend = "setuptools.build_meta"
4 |
5 | [project]
6 | name = "woe_credit_scoring"
7 | version = "2.0.4"
8 | description = "A toolkit for Credit Scoring using Weight of Evidence (WoE) and Logistic Regression"
9 | readme = "README.md"
10 | requires-python = ">=3.10"
11 | classifiers = [
12 | "Programming Language :: Python :: 3",
13 | "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
14 | "Operating System :: OS Independent",
15 | ]
16 | dependencies = [
17 | "numpy>=1.21.0",
18 | "pandas>=1.3.0",
19 | "scikit-learn>=1.0.0",
20 | "seaborn>=0.11.0",
21 | "matplotlib>=3.4.0",
22 | "scipy>=1.7.0",
23 | ]
24 |
25 | [project.urls]
26 | "Homepage" = "https://github.com/JGFuentesC/woe_credit_scoring"
27 | "Bug Tracker" = "https://github.com/JGFuentesC/woe_credit_scoring/issues"
28 |
29 | [tool.setuptools.packages.find]
30 | where = ["."]
31 |
32 | [tool.setuptools]
33 | py-modules = ["CreditScoringToolkit"]
34 |
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/woe_credit_scoring/reporter.py:
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1 | from typing import Union, List
2 | import pandas as pd
3 | import logging
4 |
5 | logger = logging.getLogger("CreditScoringToolkit")
6 |
7 | def frequency_table(df: pd.DataFrame, variables: Union[List[str], str]) -> None:
8 | """
9 | Displays a frequency table for the specified variables in the DataFrame.
10 |
11 | Args:
12 | df (pd.DataFrame): The input DataFrame.
13 | variables (Union[List[str], str]): List of variables (column names) to generate frequency tables for.
14 |
15 | Returns:
16 | None
17 | """
18 | if not isinstance(df, pd.DataFrame):
19 | raise TypeError("The first argument must be a pandas DataFrame.")
20 |
21 | if isinstance(variables, str):
22 | variables = [variables]
23 |
24 | if not isinstance(variables, list) or not all(isinstance(var, str) for var in variables):
25 | raise TypeError(
26 | "The second argument must be a string or a list of strings.")
27 |
28 | for variable in variables:
29 | if variable not in df.columns:
30 | logger.warning(f"{variable} not found in DataFrame columns.")
31 | continue
32 |
33 | frequency_df = df[variable].value_counts().to_frame().sort_index()
34 | frequency_df.columns = ['Abs. Freq.']
35 | frequency_df['Rel. Freq.'] = frequency_df['Abs. Freq.'] / \
36 | frequency_df['Abs. Freq.'].sum()
37 | frequency_df[['Cum. Abs. Freq.', 'Cum. Rel. Freq.']
38 | ] = frequency_df.cumsum()
39 |
40 | print(f'**** Frequency Table for {variable} ****\n')
41 | print(frequency_df)
42 | print("\n" * 3)
43 |
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/tests/unit/test_normalizer.py:
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1 |
2 | import pandas as pd
3 | import numpy as np
4 | import pytest
5 | from CreditScoringToolkit import DiscreteNormalizer
6 |
7 | @pytest.fixture
8 | def sample_data():
9 |
10 | data = {
11 | 'feature1': ['A', 'A', 'B', 'B', 'B', 'C', 'D', 'D', np.nan],
12 | 'feature2': ['X', 'X', 'Y', 'Y', 'Y', 'Y', 'Z', 'Z', 'Z']
13 | }
14 | return pd.DataFrame(data)
15 |
16 | def test_small_category_aggregation(sample_data):
17 |
18 | dn = DiscreteNormalizer(normalization_threshold=0.3, default_category='SMALL')
19 | dn.fit(sample_data[['feature1']])
20 | transformed = dn.transform(sample_data[['feature1']])
21 | expected_values = ['SMALL', 'SMALL', 'B', 'B', 'B', 'SMALL', 'SMALL', 'SMALL', 'SMALL']
22 | assert transformed['feature1'].tolist() == expected_values
23 |
24 | def test_missing_value_handling(sample_data):
25 |
26 | dn = DiscreteNormalizer(normalization_threshold=0.1)
27 | dn.fit(sample_data[['feature1']])
28 | transformed = dn.transform(sample_data[['feature1']])
29 | assert 'MISSING' in transformed['feature1'].unique()
30 | assert transformed['feature1'].iloc[8] == 'MISSING'
31 |
32 | def test_unseen_categories():
33 |
34 | train_data = pd.DataFrame({'feature1': ['A', 'A', 'B', 'B', 'B']})
35 | test_data = pd.DataFrame({'feature1': ['A', 'C', 'B']})
36 | dn = DiscreteNormalizer()
37 | dn.fit(train_data)
38 | transformed = dn.transform(test_data)
39 |
40 | assert transformed['feature1'].tolist() == ['A', 'B', 'B']
41 |
42 | def test_no_small_categories(sample_data):
43 |
44 | dn = DiscreteNormalizer(normalization_threshold=0.1)
45 | dn.fit(sample_data[['feature2']])
46 | transformed = dn.transform(sample_data[['feature2']])
47 | assert 'SMALL CATEGORIES' not in transformed['feature2'].unique()
48 | expected_values = ['X', 'X', 'Y', 'Y', 'Y', 'Y', 'Z', 'Z', 'Z']
49 | assert transformed['feature2'].tolist() == expected_values
50 |
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/tests/integration/test_autocreditscoring_pipeline.py:
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1 | import pandas as pd
2 | import pytest
3 | from sklearn.metrics import roc_auc_score
4 | from woe_credit_scoring.autocreditscoring import AutoCreditScoring
5 |
6 | @pytest.fixture(scope='module')
7 | def data():
8 |
9 | train = pd.read_csv('example_data/train.csv')
10 | valid = pd.read_csv('example_data/valid.csv')
11 | return train, valid
12 |
13 | def test_autocreditscoring_pipeline(data):
14 |
15 | train, valid = data
16 | varc = [v for v in train.columns if v.startswith('C_')]
17 | vard = [v for v in train.columns if v.startswith('D_')]
18 |
19 | # We use the original train data for fitting, the class will split it internally
20 | full_train_for_acs = pd.concat([train, valid]).reset_index(drop=True)
21 |
22 | acs = AutoCreditScoring(
23 | data=full_train_for_acs, # The class will perform its own train/test split
24 | target='TARGET',
25 | continuous_features=varc,
26 | discrete_features=vard
27 | )
28 |
29 | fit_params = {
30 | 'iv_feature_threshold': 0.1,
31 | 'max_discretization_bins': 5,
32 | 'discretization_method': 'quantile',
33 | 'create_reporting': False,
34 | 'target_proportion_tolerance': 0.1 # Increase tolerance for small dataset
35 | }
36 | acs.fit(**fit_params)
37 |
38 |
39 | assert acs.credit_scoring.scorecard is not None
40 | assert not acs.credit_scoring.scorecard.empty
41 |
42 | # Use the original validation set for prediction
43 | predictions = acs.predict(valid)
44 | assert 'score' in predictions.columns
45 |
46 | # To get probabilities, we must manually apply the pipeline and use the fitted model
47 | # Accessing private method for testing purposes
48 | valid_woe = acs._AutoCreditScoring__apply_pipeline(valid)
49 | valid_proba = acs.model.predict_proba(valid_woe)[:, 1]
50 |
51 | auc = roc_auc_score(y_true=valid['TARGET'], y_score=valid_proba)
52 |
53 | assert auc > 0.65
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/tests/unit/test_feature_selectors.py:
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1 |
2 | import pandas as pd
3 | import numpy as np
4 | import pytest
5 | from CreditScoringToolkit import WoeDiscreteFeatureSelector, WoeContinuousFeatureSelector
6 |
7 | @pytest.fixture
8 | def feature_selection_data():
9 |
10 | data = {
11 | 'discrete_feature_good': ['A'] * 5 + ['B'] * 5,
12 | 'discrete_feature_bad': ['C'] * 9 + ['D'] * 1,
13 | 'continuous_feature_good': np.arange(10),
14 | 'continuous_feature_bad': np.concatenate([np.zeros(9), np.ones(1)]),
15 | 'target': [0,0,0,0,1, 0,1,1,1,1]
16 | }
17 | return pd.DataFrame(data)
18 |
19 | def test_woe_discrete_feature_selector(feature_selection_data):
20 |
21 | selector = WoeDiscreteFeatureSelector()
22 | selector.fit(
23 | feature_selection_data[['discrete_feature_good', 'discrete_feature_bad']],
24 | feature_selection_data['target'],
25 | iv_threshold=0.1
26 | )
27 |
28 | assert 'discrete_feature_good' in selector.selected_features
29 | assert 'discrete_feature_bad' not in selector.selected_features
30 |
31 | transformed = selector.transform(feature_selection_data[['discrete_feature_good', 'discrete_feature_bad']])
32 | assert list(transformed.columns) == ['discrete_feature_good']
33 |
34 | def test_woe_continuous_feature_selector(feature_selection_data):
35 |
36 | selector = WoeContinuousFeatureSelector()
37 | selector.fit(
38 | feature_selection_data[['continuous_feature_good', 'continuous_feature_bad']],
39 | feature_selection_data['target'],
40 | iv_threshold=0.1,
41 | method='quantile',
42 | max_bins=2
43 | )
44 |
45 | assert len(selector.selected_features) == 1
46 | assert selector.selected_features[0]['root_feature'] == 'continuous_feature_good'
47 |
48 | transformed = selector.transform(feature_selection_data[['continuous_feature_good', 'continuous_feature_bad']])
49 |
50 |
51 | assert any(col.startswith('disc_continuous_feature_good') for col in transformed.columns)
52 | assert not any(col.startswith('disc_continuous_feature_bad') for col in transformed.columns)
53 |
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/tests/integration/test_manual_pipeline.py:
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1 |
2 | import pandas as pd
3 | import pytest
4 | from sklearn.linear_model import LogisticRegression
5 | from sklearn.metrics import roc_auc_score
6 |
7 | from CreditScoringToolkit import (
8 | DiscreteNormalizer,
9 | WoeEncoder,
10 | WoeContinuousFeatureSelector,
11 | WoeDiscreteFeatureSelector,
12 | CreditScoring
13 | )
14 |
15 | @pytest.fixture(scope='module')
16 | def data():
17 |
18 | train = pd.read_csv('example_data/train.csv')
19 | valid = pd.read_csv('example_data/valid.csv')
20 | return train, valid
21 |
22 | def test_manual_pipeline_auc(data):
23 |
24 | train, valid = data
25 |
26 | vard = [v for v in train.columns if v.startswith('D_')]
27 | varc = [v for v in train.columns if v.startswith('C_')]
28 |
29 | # 1. Normalization
30 | dn = DiscreteNormalizer(normalization_threshold=0.05, default_category='SMALL CATEGORIES')
31 | dn.fit(train[vard])
32 | train_norm = dn.transform(train[vard])
33 | valid_norm = dn.transform(valid[vard])
34 |
35 | # 2. Feature Selection
36 | wcf = WoeContinuousFeatureSelector()
37 | wdf = WoeDiscreteFeatureSelector()
38 |
39 | wcf.fit(train[varc], train['TARGET'], method='quantile', iv_threshold=0.1, max_bins=5)
40 | wdf.fit(train_norm, train['TARGET'], iv_threshold=0.1)
41 |
42 | train_selected = pd.concat([wdf.transform(train_norm), wcf.transform(train[varc])], axis=1)
43 | valid_selected = pd.concat([wdf.transform(valid_norm), wcf.transform(valid[varc])], axis=1)
44 |
45 | features = list(train_selected.columns)
46 | assert len(features) > 0
47 |
48 | # 3. WoE Encoding
49 | we = WoeEncoder()
50 | we.fit(train_selected, train['TARGET'])
51 |
52 | train_woe = we.transform(train_selected)
53 | valid_woe = we.transform(valid_selected)
54 |
55 | # 4. Model Training
56 | lr = LogisticRegression()
57 | lr.fit(train_woe, train['TARGET'])
58 |
59 | # 5. Scoring and Validation
60 | cs = CreditScoring()
61 | cs.fit(train_woe, we, lr)
62 |
63 | valid_pred_proba = lr.predict_proba(valid_woe)[:, 1]
64 | auc = roc_auc_score(y_true=valid['TARGET'], y_score=valid_pred_proba)
65 |
66 | assert auc > 0.65
67 | assert cs.scorecard is not None
68 | assert not cs.scorecard.empty
69 |
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/.gitignore:
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1 | # Byte-compiled / optimized / DLL files
2 | **/__pycache__/
3 | *.py[cod]
4 | *$py.class
5 |
6 | # Distribution / packaging
7 | .Python
8 | build/
9 | develop-eggs/
10 | dist/
11 | downloads/
12 | eggs/
13 | .eggs/
14 | lib/
15 | lib64/
16 | parts/
17 | sdist/
18 | var/
19 | wheels/
20 | pip-wheel-metadata/
21 | share/python-wheels/
22 | *.egg-info/
23 | .installed.cfg
24 | *.egg
25 | MANIFEST
26 |
27 | # PyInstaller
28 | # Usually these files are written by a python script from a template
29 | # before PyInstaller builds the exe, so as to inject date/other infos into it.
30 | *.manifest
31 | *.spec
32 |
33 | # Installer logs
34 | pip-log.txt
35 | pip-delete-this-directory.txt
36 |
37 | # Unit test / coverage reports
38 | htmlcov/
39 | .tox/
40 | .nox/
41 | .coverage
42 | .coverage.*
43 | .cache
44 | nosetests.xml
45 | coverage.xml
46 | *.cover
47 | *.py,cover
48 | .hypothesis/
49 | .pytest_cache/
50 |
51 | # Translations
52 | *.mo
53 | *.pot
54 |
55 | # Django stuff:
56 | *.log
57 | local_settings.py
58 | db.sqlite3
59 | db.sqlite3-journal
60 |
61 | # Flask stuff:
62 | instance/
63 | .webassets-cache
64 |
65 | # Scrapy stuff:
66 | .scrapy
67 |
68 | # PyBuilder
69 | target/
70 |
71 | # Jupyter Notebook
72 | .ipynb_checkpoints
73 |
74 | # IPython
75 | profile_default/
76 | ipython_config.py
77 |
78 | # pyenv
79 | .python-version
80 |
81 | # pipenv
82 | # According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
83 | # However, in case of collaboration, if having platform-specific dependencies or dependencies
84 | # having no cross-platform support, pipenv may install dependencies that don't work, or not
85 | # install all needed dependencies.
86 | #Pipfile.lock
87 |
88 | # PEP 582; used by e.g. github.com/David-OConnor/pyflow
89 | __pypackages__/
90 |
91 | # Celery stuff
92 | celerybeat-schedule
93 | celerybeat.pid
94 |
95 | # SageMath parsed files
96 | *.sage.py
97 |
98 | # Environments
99 | .env
100 | .venv
101 | env/
102 | venv/
103 | ENV/
104 | env.bak/
105 | venv.bak/
106 |
107 | # Spyder project settings
108 | .spyderproject
109 | .spyproject
110 |
111 | # Rope project settings
112 | .ropeproject
113 |
114 | # mkdocs documentation
115 | /site
116 |
117 | # mypy
118 | .mypy_cache/
119 | .dmypy.json
120 | dmypy.json
121 |
122 | # Pyre type checker
123 | .pyre/
124 |
125 | #pip
126 |
127 | **/.venv/
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/woe_credit_scoring/base.py:
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1 | from typing import Union
2 | import numpy as np
3 | import pandas as pd
4 |
5 | class WoeBaseFeatureSelector:
6 | """
7 | Base class for selecting features based on their Weight of Evidence (WoE)
8 | transformation and Information Value (IV) statistic.
9 |
10 | This class provides foundational methods for evaluating and selecting
11 | features by transforming them using WoE and calculating their IV.
12 | The IV statistic is used to measure the predictive power of each feature
13 | with respect to a binary target variable. Features with higher IV values
14 | are considered more predictive.
15 |
16 | The class includes methods to compute the IV statistic, check for
17 | monotonic risk behavior, and other utility functions that can be extended
18 | by subclasses to implement specific feature selection strategies.
19 |
20 | Attributes:
21 | None
22 |
23 | Methods:
24 | _information_value(X, y): Computes the IV statistic for a given feature.
25 | _check_monotonic(X, y): Checks if a feature exhibits monotonic risk behavior.
26 | """
27 |
28 | def __init__(self):
29 | pass
30 |
31 | @staticmethod
32 | def _information_value(X: pd.Series, y: pd.Series) -> Union[float, None]:
33 | """
34 | Computes information value (IV) statistic.
35 |
36 | Args:
37 | X (pd.Series): Discretized predictors data.
38 | y (pd.Series): Dichotomic response feature.
39 |
40 | Returns:
41 | Union[float, None]: IV statistic or None if IV is infinite.
42 |
43 | Reference:
44 | For more details on the Information Value statistic, see
45 | http://arxiv.org/pdf/2309.13183
46 | """
47 | aux = pd.concat([X, y], axis=1)
48 | aux.columns = ['x', 'y']
49 | aux = aux.assign(nrow=1)
50 | aux = aux.pivot_table(index='x', columns='y',
51 | values='nrow', aggfunc='sum', fill_value=0)
52 | aux /= aux.sum()
53 | aux['woe'] = np.log(aux[0] / aux[1])
54 | aux['iv'] = (aux[0] - aux[1]) * aux['woe']
55 | iv = aux['iv'].sum()
56 | return None if np.isinf(iv) else iv
57 |
58 | @staticmethod
59 | def _check_monotonic(X: pd.Series, y: pd.Series) -> bool:
60 | """
61 | Validates if a given discretized feature has monotonic risk behavior.
62 |
63 | Args:
64 | X (pd.Series): Discretized predictors data.
65 | y (pd.Series): Dichotomic response feature.
66 |
67 | Returns:
68 | bool: Whether or not the feature has monotonic risk.
69 | """
70 | aux = pd.concat([X, y], axis=1)
71 | aux.columns = ['x', 'y']
72 | aux = aux.loc[aux['x'] != 'MISSING'].reset_index(drop=True)
73 | aux = aux.groupby('x').mean()
74 | y_values = list(aux['y'])
75 | return (len(y_values) >= 2) and (sorted(y_values) == y_values or sorted(y_values, reverse=True) == y_values)
76 |
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/tests/unit/test_encoder.py:
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1 |
2 | import pandas as pd
3 | import numpy as np
4 | import pytest
5 | from CreditScoringToolkit import WoeEncoder
6 |
7 | @pytest.fixture
8 | def woe_data():
9 |
10 | data = {
11 | 'feature': ['A', 'A', 'A', 'B', 'B', 'C', 'C', 'C', 'C'],
12 | 'target': [0, 0, 1, 0, 1, 0, 1, 1, 1]
13 | }
14 | return pd.DataFrame(data)
15 |
16 | def test_woe_calculation(woe_data):
17 |
18 | encoder = WoeEncoder()
19 | encoder.fit(woe_data[['feature']], woe_data['target'])
20 | woe_table = pd.DataFrame.from_dict(encoder._woe_encoding_map['feature'], orient='index', columns=['woe'])
21 |
22 |
23 |
24 | # Correct WoE is log( P(0) / P(1) )
25 | p0 = woe_data['target'].value_counts(normalize=True)[0]
26 | p1 = 1 - p0
27 |
28 | # For category A
29 | p0_A = woe_data[woe_data['feature'] == 'A']['target'].value_counts(normalize=True)[0]
30 | p1_A = 1 - p0_A
31 | expected_A = np.log((p0_A / p0) / (p1_A / p1)) if p1_A > 0 and p0_A > 0 else 0
32 |
33 | # For category B
34 | p0_B = woe_data[woe_data['feature'] == 'B']['target'].value_counts(normalize=True)[0]
35 | p1_B = 1 - p0_B
36 | expected_B = np.log((p0_B / p0) / (p1_B / p1)) if p1_B > 0 and p0_B > 0 else 0
37 |
38 | # For category C
39 | p0_C = woe_data[woe_data['feature'] == 'C']['target'].value_counts(normalize=True)[0]
40 | p1_C = 1 - p0_C
41 | expected_C = np.log((p0_C / p0) / (p1_C / p1)) if p1_C > 0 and p0_C > 0 else 0
42 |
43 | assert np.isclose(woe_table.loc['A', 'woe'], np.log( (2/4) / (1/5)))
44 | assert np.isclose(woe_table.loc['B', 'woe'], np.log( (1/4) / (1/5)))
45 | assert np.isclose(woe_table.loc['C', 'woe'], np.log( (1/4) / (3/5)))
46 |
47 | def test_woe_transform(woe_data):
48 |
49 | encoder = WoeEncoder()
50 | encoder.fit(woe_data[['feature']], woe_data['target'])
51 | transformed = encoder.transform(woe_data[['feature']])
52 |
53 | # Correct WoE is log(% of 0s / % of 1s)
54 | # P(0|A) = 2/4 = 0.5, P(1|A) = 1/5 = 0.2 -> log(0.5/0.2) is not right
55 | # It should be log ( (count_0 / total_0) / (count_1 / total_1) )
56 | total_0 = 4
57 | total_1 = 5
58 |
59 | p0_A = (2/total_0)
60 | p1_A = (1/total_1)
61 | expected_A = np.log(p0_A / p1_A)
62 |
63 | p0_B = (1/total_0)
64 | p1_B = (1/total_1)
65 | expected_B = np.log(p0_B / p1_B)
66 |
67 | p0_C = (1/total_0)
68 | p1_C = (3/total_1)
69 | expected_C = np.log(p0_C / p1_C)
70 |
71 | assert np.isclose(transformed['feature'].iloc[0], expected_A)
72 | assert np.isclose(transformed['feature'].iloc[3], expected_B)
73 | assert np.isclose(transformed['feature'].iloc[5], expected_C)
74 |
75 | def test_woe_inverse_transform(woe_data):
76 |
77 | encoder = WoeEncoder()
78 | encoder.fit(woe_data[['feature']], woe_data['target'])
79 | transformed = encoder.transform(woe_data[['feature']])
80 | inversed = encoder.inverse_transform(transformed)
81 |
82 | pd.testing.assert_frame_equal(inversed, woe_data[['feature']])
83 |
84 | def test_woe_with_missing_values():
85 |
86 | data = {
87 | 'feature': ['A', 'A', 'B', 'MISSING'],
88 | 'target': [0, 1, 0, 1]
89 | }
90 | df = pd.DataFrame(data)
91 | encoder = WoeEncoder()
92 | encoder.fit(df[['feature']], df['target'])
93 | transformed = encoder.transform(df[['feature']])
94 |
95 | assert 'MISSING' in encoder._woe_encoding_map['feature']
96 | assert not transformed.isnull().values.any()
97 |
--------------------------------------------------------------------------------
/woe_credit_scoring/encoder.py:
--------------------------------------------------------------------------------
1 | from typing import Dict
2 | from collections import ChainMap
3 | import numpy as np
4 | import pandas as pd
5 |
6 | class WoeEncoder:
7 | """
8 | WoeEncoder is a class for encoding discrete features into Weight of Evidence (WoE) values.
9 |
10 | WoE is a commonly used technique in credit scoring and other binary classification problems.
11 | It transforms categorical features into continuous values based on the log odds of the target variable.
12 |
13 | This class provides methods to fit the WoE transformation based on input data, transform new data using the learned WoE encoding,
14 | and inverse transform WoE encoded data back to the original categorical values.
15 |
16 | Attributes:
17 | features (list): List of feature names to be encoded.
18 | _woe_encoding_map (dict): Dictionary mapping features to their WoE encoding.
19 | __is_fitted (bool): Flag indicating whether the encoder has been fitted.
20 | _woe_reverse_map (dict): Dictionary mapping WoE values back to original feature values.
21 |
22 | Reference:
23 | For more details on the Weight of Evidence (WoE) encoding, see
24 | http://listendata.com/2015/03/weight-of-evidence-woe-and-information.html
25 | """
26 |
27 | def __init__(self) -> None:
28 | self.features = None
29 | self._woe_encoding_map = None
30 | self.__is_fitted = False
31 | self._woe_reverse_map = None
32 |
33 | def fit(self, X: pd.DataFrame, y: pd.Series, target_col: str = 'binary_target') -> None:
34 | """Learns WoE encoding.
35 |
36 | Args:
37 | X (pd.DataFrame): Data with discrete features.
38 | y (pd.Series): Dichotomic response.
39 | target_col (str): Name of the target column to be created in the dataframe.
40 | """
41 | aux = X.copy()
42 | self.features = list(aux.columns)
43 | aux[target_col] = y
44 | self._woe_encoding_map = dict(ChainMap(
45 | *map(lambda feature: self._woe_transformation(aux, feature, target_col), self.features)))
46 | self.__is_fitted = True
47 |
48 | @staticmethod
49 | def _woe_transformation(X: pd.DataFrame, feature: str, bin_target: str) -> Dict[str, Dict]:
50 | """Calculates WoE Map between discrete space and log odds space.
51 |
52 | Args:
53 | X (pd.DataFrame): Discrete data including dichotomic response feature.
54 | feature (str): Name of the feature for getting the map.
55 | bin_target (str): Name of the dichotomic response feature.
56 |
57 | Returns:
58 | dict: Key is the name of the feature, value is the WoE Map.
59 |
60 | Raises:
61 | ValueError: If bin_target column has more than 2 categories.
62 | """
63 | if X[bin_target].nunique() != 2:
64 | raise ValueError(
65 | f"The target column '{bin_target}' must have exactly 2 unique values.")
66 |
67 | aux = X[[feature, bin_target]].copy().assign(n_row=1)
68 | aux = aux.pivot_table(index=feature, columns=bin_target,
69 | values='n_row', aggfunc='sum', fill_value=0)
70 | aux /= aux.sum()
71 | aux['woe'] = np.log(aux[0] / aux[1])
72 | aux = aux.drop(columns=[0, 1])
73 | return {feature: aux['woe'].to_dict()}
74 |
75 | def transform(self, X: pd.DataFrame) -> pd.DataFrame:
76 | """Performs WoE transformation.
77 |
78 | Args:
79 | X (pd.DataFrame): Discrete data to be transformed.
80 |
81 | Raises:
82 | Exception: If fit method not called previously.
83 |
84 | Returns:
85 | pd.DataFrame: WoE encoded data.
86 | """
87 | if not self.__is_fitted:
88 | raise Exception(
89 | 'Please call fit method first with the required parameters')
90 |
91 | aux = X.copy()
92 | for feature, woe_map in self._woe_encoding_map.items():
93 | aux[feature] = aux[feature].replace(woe_map)
94 | return aux
95 |
96 | def inverse_transform(self, X: pd.DataFrame) -> pd.DataFrame:
97 | """Performs Inverse WoE transformation.
98 |
99 | Args:
100 | X (pd.DataFrame): WoE data to be transformed.
101 |
102 | Raises:
103 | Exception: If fit method not called previously.
104 |
105 | Returns:
106 | pd.DataFrame: WoE encoded data.
107 | """
108 | if not self.__is_fitted:
109 | raise Exception(
110 | 'Please call fit method first with the required parameters')
111 |
112 | aux = X.copy()
113 | self._woe_reverse_map = {feature: {v: k for k, v in woe_map.items(
114 | )} for feature, woe_map in self._woe_encoding_map.items()}
115 | for feature, woe_map in self._woe_reverse_map.items():
116 | aux[feature] = aux[feature].replace(woe_map)
117 | return aux
118 |
--------------------------------------------------------------------------------
/woe_credit_scoring/scoring.py:
--------------------------------------------------------------------------------
1 | from typing import Optional, Dict
2 | from collections import ChainMap
3 | import numpy as np
4 | import pandas as pd
5 | from sklearn.linear_model import LogisticRegression
6 | import logging
7 | from .encoder import WoeEncoder
8 |
9 | logger = logging.getLogger("CreditScoringToolkit")
10 |
11 | class CreditScoring:
12 | """
13 | Implements credit risk scorecards following the methodology proposed in
14 | Siddiqi, N. (2012). Credit risk scorecards: developing and implementing intelligent credit scoring (Vol. 3). John Wiley & Sons.
15 |
16 | This class provides methods to fit a logistic regression model to the provided data,
17 | transform the data using Weight of Evidence (WoE) encoding, and generate a scorecard
18 | that maps the model's coefficients to a scoring system. The scorecard can then be used
19 | to convert new data into credit scores.
20 |
21 | Attributes:
22 | logistic_regression (Optional[LogisticRegression]): Fitted logistic regression model.
23 | pdo (Optional[int]): Points to Double the Odds.
24 | base_odds (Optional[int]): Base odds at the base score.
25 | base_score (Optional[int]): Base score for calibration.
26 | betas (Optional[list]): Coefficients of the logistic regression model.
27 | alpha (Optional[float]): Intercept of the logistic regression model.
28 | factor (Optional[float]): Factor used in score calculation.
29 | offset (Optional[float]): Offset used in score calculation.
30 | features (Optional[Dict[str, float]]): Mapping of feature names to their coefficients.
31 | n (Optional[int]): Number of features.
32 | scorecard (Optional[pd.DataFrame]): DataFrame containing the scorecard.
33 | scoring_map (Optional[Dict[str, Dict[str, int]]]): Mapping of features to their score mappings.
34 | __is_fitted (bool): Indicates whether the model has been fitted.
35 | """
36 |
37 | logistic_regression: Optional[LogisticRegression] = None
38 | pdo: Optional[int] = None
39 | base_odds: Optional[int] = None
40 | base_score: Optional[int] = None
41 | betas: Optional[list] = None
42 | alpha: Optional[float] = None
43 | factor: Optional[float] = None
44 | offset: Optional[float] = None
45 | features: Optional[Dict[str, float]] = None
46 | n: Optional[int] = None
47 | scorecard: Optional[pd.DataFrame] = None
48 | scoring_map: Optional[Dict[str, Dict[str, int]]] = None
49 | __is_fitted: bool = False
50 |
51 | def __init__(self, pdo: int = 20, base_score: int = 400, base_odds: int = 1) -> None:
52 | """Initializes Credit Scoring object.
53 |
54 | Args:
55 | pdo (int, optional): Points to Double the Odd's _. Defaults to 20.
56 | base_score (int, optional): Default score for calibration. Defaults to 400.
57 | base_odds (int, optional): Odd's base at base_score . Defaults to 1.
58 | """
59 | self.pdo = pdo
60 | self.base_score = base_score
61 | self.base_odds = base_odds
62 | self.factor = self.pdo / np.log(2)
63 | self.offset = self.base_score - self.factor * np.log(self.base_odds)
64 |
65 | @staticmethod
66 | def _get_scorecard(X: pd.DataFrame, feature: str) -> pd.DataFrame:
67 | """Generates scorecard points for a given feature
68 |
69 | Args:
70 | X (pd.DataFrame): Feature Data
71 | feature (str): Predictor
72 |
73 | Returns:
74 | pd.DataFrame: Feature, Attribute and respective points
75 | """
76 | sc = X[[feature, f'P_{feature}']].copy(
77 | ).drop_duplicates().reset_index(drop=True)
78 | sc = sc.rename(columns={feature: 'attribute',
79 | f'P_{feature}': 'points'})
80 | sc.insert(0, 'feature', feature)
81 | return sc
82 |
83 | def fit(self, Xw: pd.DataFrame, woe_encoder: WoeEncoder, logistic_regression: LogisticRegression) -> None:
84 | """Learns scoring map
85 |
86 | Args:
87 | Xw (pd.DataFrame): WoE transformed data
88 | woe_encoder (WoeEncoder): WoE encoder fitted object
89 | logistic_regression (LogisticRegression): Fitted logistic regression model
90 | """
91 | X = Xw.copy()
92 | self.betas = list(logistic_regression.coef_[0])
93 | self.alpha = logistic_regression.intercept_[0]
94 | self.features = dict(zip(Xw.columns, self.betas))
95 | self.n = len(self.betas)
96 | for feature, beta in self.features.items():
97 | X[f'P_{feature}'] = np.floor(
98 | (-X[feature] * beta + self.alpha / self.n) * self.factor + self.offset / self.n).astype(int)
99 | features = list(self.features.keys())
100 | X[features] = woe_encoder.inverse_transform(X[features])
101 | self.scorecard = pd.concat(
102 | map(lambda f: self._get_scorecard(X, f), features))
103 | self.scorecard = self.scorecard.groupby(['feature', 'attribute']).max()
104 | self.scoring_map = dict(ChainMap(*[{f: d[['attribute', 'points']].set_index('attribute')[
105 | 'points'].to_dict()} for f, d in self.scorecard.reset_index().groupby('feature')]))
106 | self.__is_fitted = True
107 |
108 | def transform(self, X: pd.DataFrame) -> pd.DataFrame:
109 | """Converts discrete data to scores
110 |
111 | Args:
112 | X (pd.DataFrame): Discrete predictor data
113 |
114 | Raises:
115 | Exception: If fit method is not called first.
116 | Exception: If a fitted feature is not present in data.
117 |
118 | Returns:
119 | pd.DataFrame: Total score and scores for each feature
120 | """
121 | if not self.__is_fitted:
122 | raise Exception(
123 | 'Please call fit method first with the required parameters')
124 | else:
125 | aux = X.copy()
126 | features = list(self.scoring_map.keys())
127 | non_present_features = [
128 | f for f in features if f not in aux.columns]
129 | if len(non_present_features) > 0:
130 | logger.exception(
131 | f'{",".join(non_present_features)} feature{"s" if len(non_present_features) > 1 else ""} not present in data')
132 | raise Exception("Missing features")
133 | else:
134 | for feature, points_map in self.scoring_map.items():
135 | aux[feature] = aux[feature].replace(points_map)
136 | aux['score'] = aux[features].sum(axis=1)
137 | return aux
138 |
--------------------------------------------------------------------------------
/woe_credit_scoring/normalizer.py:
--------------------------------------------------------------------------------
1 | from typing import Dict
2 | from collections import ChainMap
3 | from itertools import repeat
4 | import numpy as np
5 | import pandas as pd
6 |
7 | class DiscreteNormalizer:
8 | """
9 | DiscreteNormalizer is a class for normalizing discrete data based on a specified relative frequency threshold.
10 |
11 | This class provides methods to fit a normalization model to discrete data and transform the data according to the learned normalization mapping.
12 | It handles missing values by assigning them to a specific category and groups infrequent categories into a default category.
13 | If the default category does not meet the relative frequency threshold, it is mapped to the most frequent category.
14 |
15 | Attributes:
16 | MISSING_VALUE (str): Placeholder for missing values.
17 | DEFAULT_THRESHOLD (float): Default threshold for considering a category as relevant.
18 | normalization_threshold (float): Threshold for considering a category as relevant.
19 | default_category (str): Name for the default grouping/new categories.
20 | normalization_map (dict): Mapping of original categories to normalized categories.
21 | features (list): List of feature names in the input data.
22 | new_categories (dict): Dictionary of new categories identified during transformation.
23 | X (pd.DataFrame): The input data used for fitting the model.
24 | __is_fitted (bool): Flag indicating whether the model has been fitted.
25 |
26 | Methods:
27 | fit(X): Learns discrete normalization mapping from the input data.
28 | transform(X): Transforms discrete data into its normalized form.
29 | _prepare_feature(feature): Prepares a feature by filling missing values and converting to string.
30 | _get_normalization_map(X, feature, threshold, default_category): Creates the normalization map for a given feature.
31 | """
32 | MISSING_VALUE = 'MISSING'
33 | DEFAULT_THRESHOLD = 0.05
34 |
35 | def __init__(self, normalization_threshold: float = DEFAULT_THRESHOLD, default_category: str = 'OTHER') -> None:
36 | """
37 | Args:
38 | normalization_threshold (float, optional): Threshold for considering a category as relevant. Defaults to 0.05.
39 | default_category (str, optional): Given name for the default grouping/new categories. Defaults to 'OTHER'.
40 | """
41 | self.__is_fitted = False
42 | self.normalization_threshold = normalization_threshold
43 | self.default_category = default_category
44 | self.normalization_map = None
45 | self.features = None
46 | self.new_categories = {}
47 | self.X = None
48 |
49 | def fit(self, X: pd.DataFrame) -> None:
50 | """Learns discrete normalization mapping taking into account the following rules:
51 | 1. All missing values will be filled with the category 'MISSING'
52 | 2. Categories which relative frequency is less than normalization threshold will be mapped to default_category
53 | 3. If default_category as a group doesn't reach the relative frequency threshold, then it will be mapped to the most frequent category
54 |
55 | Args:
56 | X (pd.DataFrame): Data to be normalized
57 |
58 | Raises:
59 | TypeError: If provided data is not a pandas DataFrame object
60 | """
61 | if not isinstance(X, pd.DataFrame):
62 | raise TypeError('Please use a Pandas DataFrame object')
63 |
64 | self.X = X.copy()
65 | self.features = list(self.X.columns)
66 | self.normalization_map = {}
67 |
68 | for feat in self.features:
69 | self.X[feat] = self._prepare_feature(self.X[feat])
70 |
71 | self.normalization_map = dict(ChainMap(*map(
72 | lambda feat: self._get_normalization_map(
73 | self.X, feat, self.normalization_threshold, self.default_category),
74 | self.features
75 | )))
76 | self.__is_fitted = True
77 |
78 | @staticmethod
79 | def _prepare_feature(feature: pd.Series) -> pd.Series:
80 | """Prepares a feature by filling missing values and converting to string."""
81 | return feature.fillna(DiscreteNormalizer.MISSING_VALUE).astype(str)
82 |
83 | @staticmethod
84 | def _get_normalization_map(X: pd.DataFrame, feature: str, threshold: float, default_category: str) -> Dict:
85 | """Creates the normalization map and the list of existing categories for a given feature.
86 |
87 | Args:
88 | X (pd.DataFrame): Data with discrete features
89 | feature (str): Feature to be analyzed
90 | threshold (float): Threshold for considering a category as relevant. Defaults to 0.05.
91 | default_category (str): Given name for the default grouping/new categories. Defaults to 'OTHER'.
92 |
93 | Returns:
94 | dict: Feature is the key and value is a dictionary which keys are the replacement map and the list of existing categories.
95 | """
96 | aux = X[feature].value_counts(normalize=True).to_frame()
97 | aux.columns = [feature]
98 | aux['mapping'] = np.where(
99 | aux[feature] < threshold, default_category, aux.index)
100 | mode = aux.head(1)['mapping'].values[0]
101 |
102 | if aux.loc[aux['mapping'] == default_category][feature].sum() < threshold:
103 | aux['mapping'] = aux['mapping'].replace({default_category: mode})
104 |
105 | aux = aux.drop(feature, axis=1)
106 | return {
107 | feature: {
108 | 'replacement_map': aux.loc[aux.index != aux['mapping']]['mapping'].to_dict(),
109 | 'existing_categories': list(aux.index),
110 | 'mode': mode
111 | }
112 | }
113 |
114 | def transform(self, X: pd.DataFrame) -> pd.DataFrame:
115 | """Transforms discrete data into its normalized form.
116 |
117 | Args:
118 | X (pd.DataFrame): Data to be transformed
119 |
120 | Raises:
121 | Exception: If fit method not called previously
122 | Exception: If features analyzed during fit are not present in X
123 |
124 | Returns:
125 | pd.DataFrame: Normalized discrete data
126 | """
127 | if not self.__is_fitted:
128 | raise Exception(
129 | 'Please call fit method first with the required parameters')
130 |
131 | aux = X.copy()
132 | features = list(self.normalization_map.keys())
133 | non_present_features = [f for f in features if f not in X.columns]
134 |
135 | if non_present_features:
136 | raise Exception(
137 | f"Missing features: {', '.join(non_present_features)}")
138 |
139 | for feat in features:
140 | aux[feat] = self._prepare_feature(aux[feat])
141 | mapping = self.normalization_map[feat]['replacement_map']
142 | existing_categories = self.normalization_map[feat]['existing_categories']
143 | new_categories = [
144 | cat for cat in aux[feat].unique() if cat not in existing_categories]
145 |
146 | if new_categories:
147 | self.new_categories.update({feat: new_categories})
148 | replacement = self.default_category if self.default_category in existing_categories else self.normalization_map[
149 | feat]['mode']
150 | aux[feat] = aux[feat].replace(
151 | dict(zip(new_categories, repeat(replacement))))
152 |
153 | aux[feat] = aux[feat].replace(mapping)
154 |
155 | return aux
156 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 |
2 |
3 |
4 |
5 |
6 | [![Contributors][contributors-shield]][contributors-url]
7 |
8 | [![Forks][forks-shield]][forks-url]
9 |
10 | [![Stargazers][stars-shield]][stars-url]
11 |
12 | [![Issues][issues-shield]][issues-url]
13 |
14 | [![GPLv3 License][license-shield]][license-url]
15 |
16 | [![LinkedIn][linkedin-shield]][linkedin-url]
17 |
18 |
19 |
20 | Credit Scoring Toolkit
21 |
22 |
23 |
24 |
25 |
26 | In finance is a common practice to create risk scorecards to assess the credit worthiness for a given customer. Unfortunately, out of the box credit scoring tools are quite expensive and scatter, that's why we created this toolkit: to empower all credit scoring practicioners and spread the use of weight of evidence based scoring techniques for alternative uses cases (virtually any binary classification problem).
27 |
28 |
29 | Explore the documentation»
30 |
31 | Report Bug
32 |
33 | Request Feature
34 |
35 |
36 |
37 |
38 |
39 |
40 | Table of Contents
41 |
42 | - About The Project
43 |
44 | - Discrete Normalizer
45 | - Discretizer
46 | - WoeEncoder
47 | - WoeBaseFeatureSelector
48 | - WoeContinuousFeatureSelector
49 | - WoeDiscreteFeatureSelector
50 | - CreditScoring
51 | - IVCalculator
52 | - Built With
53 |
54 | - Installation
55 | - Usage
56 | - Contributing
57 | - License
58 | - Contact
59 | - Citing
60 | - Acknowledgments
61 |
62 |
63 |
64 |
65 | ## About The Project
66 |
67 | The general process for creating Weight of Evidence based scorecards is illustrated in the figure below :
68 |
69 | 
70 |
71 | For that matter, we implemented the following classes to address the necesary steps to perform
72 | credit scoring transformation:
73 |
74 | ### DiscreteNormalizer
75 | Class for normalizing discrete data for a given relative frequency threshold
76 | ### Discretizer
77 | Class for discretizing continuous data into bins using several methods
78 | ### WoeEncoder
79 | Class for encoding discrete features into Weight of Evidence(WoE) transformation
80 | ### WoeBaseFeatureSelector
81 | Base class for selecting features based on their WoE transformation and
82 | Information Value statistic.
83 | ### WoeContinuousFeatureSelector
84 | Class for selecting continuous features based on their WoE transformation and
85 | Information Value statistic.
86 | ### WoeDiscreteFeatureSelector
87 | Class for selecting discrete features based on their WoE transformation and
88 | Information Value statistic.
89 | ### CreditScoring
90 | Implements credit risk scorecards following the methodology proposed in
91 | Siddiqi, N. (2012). Credit risk scorecards: developing and implementing intelligent credit scoring (Vol. 3). John Wiley & Sons.
92 | ### IVCalculator
93 | A utility class to quickly calculate Information Value (IV) for both continuous and discrete features. This class provides a simple interface that abstracts away the manual steps of discretization and normalization, making it easy to assess feature predictive power.
94 |
95 | ### Built With
96 |
97 | * [Python](https://www.python.org/)
98 | * [Numpy](https://numpy.org/)
99 | * [Pandas](https://pandas.pydata.org/)
100 | * [Jupyter](https://jupyter.org/)
101 | * [Scikit-Learn](https://scikit-learn.org/stable/)
102 | * [Matplotlib](https://matplotlib.org/)
103 | * [Seaborn](https://seaborn.pydata.org/)
104 | * [SciPy](https://scipy.org/)
105 |
106 | (back to top)
107 |
108 |
109 |
110 | ## Installation
111 |
112 | You can simply install the module using pip
113 |
114 | * pip
115 |
116 | ```sh
117 |
118 | pip install woe-credit-scoring
119 |
120 | ```
121 |
122 |
123 | (back to top)
124 |
125 | ## Usage
126 |
127 | The new `AutoCreditScoring` class provides a streamlined way to train a credit scoring model, generate reports, and make predictions. Here's a quick example of how to use it:
128 |
129 | ### Dependencies
130 |
131 | ```python
132 | import pandas as pd
133 | from CreditScoringToolkit import AutoCreditScoring
134 | import warnings
135 | warnings.filterwarnings("ignore", category=UserWarning, module="sklearn.preprocessing._discretization")
136 | ```
137 |
138 | ### Reading example data
139 |
140 | ```python
141 | # Read example data for train and validation (loan applications)
142 | train = pd.read_csv('example_data/train.csv')
143 | valid = pd.read_csv('example_data/valid.csv')
144 | ```
145 |
146 | ### Defining feature type
147 |
148 | ```python
149 | # Assign features lists by type
150 | vard = [v for v in train.columns if v.startswith('D_')]
151 | varc = [v for v in train.columns if v.startswith('C_')]
152 | ```
153 |
154 | ### Automated Credit Scoring
155 |
156 | The `AutoCreditScoring` class handles the entire workflow, from feature selection and WoE transformation to model training and scoring.
157 |
158 | ```python
159 | # If you prefer, use AutoCreditScoring class to perform all the steps in a single call with additional features
160 | # like outlier detection and treatment, feature selection, reporting and more.
161 | from CreditScoringToolkit import AutoCreditScoring
162 |
163 | kwargs = {'iv_feature_threshold':0.05,
164 | 'max_discretization_bins':6,
165 | 'strictly_monotonic':True,
166 | 'create_reporting':True,
167 | 'discretization_method':'dcc'}
168 | acs = AutoCreditScoring(train,'TARGET',varc,vard)
169 | acs.fit(**kwargs)
170 |
171 | # You can also save the reports to a folder in PNG format
172 | acs.save_reports('reports')
173 | ```
174 |
175 | This will generate several reports, including:
176 |
177 | - Score distribution histograms and KDE plots
178 | - Event rate by score range plots
179 | - Feature importance based on Information Value
180 | - ROC curve for the model
181 |
182 | 
183 | 
184 | 
185 | 
186 | 
187 |
188 | ### Making Predictions
189 |
190 | Once the model is trained, you can use the `predict` method to score new data.
191 |
192 | ```python
193 | predictions = acs.predict(valid)
194 | predictions.head()
195 | ```
196 |
197 | This will return a DataFrame with the individual point contributions for each feature (`pts_*` columns) and the final score.
198 |
199 | ### IV Calculator
200 |
201 | The `IVCalculator` class provides a quick and easy way to calculate Information Value (IV) for your features without going through the entire credit scoring workflow. This is useful for initial feature analysis and selection.
202 |
203 | ```python
204 | from CreditScoringToolkit import IVCalculator
205 |
206 | # Initialize IVCalculator with your data
207 | iv_calculator = IVCalculator(
208 | data=train,
209 | target='TARGET',
210 | continuous_features=varc,
211 | discrete_features=vard
212 | )
213 |
214 | # Calculate IV for all features
215 | iv_report = iv_calculator.calculate_iv(
216 | max_discretization_bins=5,
217 | strictly_monotonic=False,
218 | discretization_method='quantile',
219 | discrete_normalization_threshold=0.05
220 | )
221 |
222 | # Display the report
223 | print(iv_report)
224 | ```
225 |
226 | The output will be a DataFrame with columns:
227 | - `feature`: Feature name
228 | - `iv`: Information Value
229 | - `feature_type`: 'continuous' or 'discrete'
230 |
231 | This allows you to quickly identify which features have the most predictive power before building your full credit scoring model.
232 |
233 | (back to top)
234 |
235 |
236 |
237 |
238 |
239 | ## Contributing
240 |
241 | If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".
242 |
243 | Don't forget to give the project a star! Thanks again!
244 |
245 | 1. Fork the Project
246 |
247 | 2. Create your Feature Branch (`git checkout -b feature/AmazingFeature`)
248 |
249 | 3. Commit your Changes (`git commit -m 'Add some AmazingFeature'`)
250 |
251 | 4. Push to the Branch (`git push origin feature/AmazingFeature`)
252 |
253 | 5. Open a Pull Request
254 |
255 | (back to top)
256 |
257 | ## License
258 |
259 | Distributed under the GNU General Public License v3.0 License. See `LICENSE` for more information.
260 | (back to top)
261 |
262 | ## Contact
263 |
264 | José G Fuentes - [@jgusteacher](https://twitter.com/jgusteacher) - jose.gustavo.fuentes@comunidad.unam.mx
265 |
266 |
267 | Project Link: [https://github.com/JGFuentesC/woe_credit_scoring](https://github.com/JGFuentesC/woe_credit_scoring)
268 |
269 | (back to top)
270 |
271 | ## Citing
272 | If you use this software in scientific publications, we would appreciate citations to the following paper:
273 |
274 | [Combination of Unsupervised Discretization Methods for Credit Risk](https://journals.plos.org/plosone/article/authors?id=10.1371/journal.pone.0289130) José G. Fuentes Cabrera, Hugo A. Pérez Vicente, Sebastián Maldonado,Jonás Velasco
275 |
276 | (back to top)
277 |
278 | ## Acknowledgments
279 |
280 |
281 | * [Siddiqi, N. (2012). Credit risk scorecards: developing and implementing intelligent credit scoring (Vol. 3). John Wiley & Sons.](https://books.google.com.mx/books?hl=es&lr=&id=SEbCeN3-kEUC&oi=fnd&pg=PT7&dq=siddiqi&ots=RvTR0RbOlQ&sig=_V4Iz1q_Hi_GwLAxrp-7tuHrOWY&redir_esc=y#v=onepage&q=siddiqi&f=false). For his amazing textbook.
282 |
283 | * [@othneildrew](https://github.com/othneildrew/Best-README-Template). For his amazing README template
284 |
285 | * [Demo data](https://www.kaggle.com/code/gauravduttakiit/risk-analytics-in-banking-financial-services-1/data). For providing example data.
286 |
287 |
288 | (back to top)
289 |
290 |
291 |
292 |
293 |
294 |
295 |
296 |
297 |
298 | [contributors-shield]: https://img.shields.io/github/contributors/JGFuentesC/woe_credit_scoring.svg?style=for-the-badge
299 |
300 | [contributors-url]: https://github.com/JGFuentesC/woe_credit_scoring/graphs/contributors
301 |
302 | [forks-shield]: https://img.shields.io/github/forks/JGFuentesC/woe_credit_scoring.svg?style=for-the-badge
303 |
304 | [forks-url]: https://github.com/JGFuentesC/woe_credit_scoring/network/members
305 |
306 | [stars-shield]: https://img.shields.io/github/stars/JGFuentesC/woe_credit_scoring.svg?style=for-the-badge
307 |
308 | [stars-url]: https://github.com/JGFuentesC/woe_credit_scoring/stargazers
309 |
310 | [issues-shield]: https://img.shields.io/github/issues/JGFuentesC/woe_credit_scoring.svg?style=for-the-badge
311 |
312 | [issues-url]: https://github.com/JGFuentesC/woe_credit_scoring/issues
313 |
314 | [license-shield]: https://img.shields.io/github/license/JGFuentesC/woe_credit_scoring.svg?style=for-the-badge
315 |
316 | [license-url]: https://github.com/JGFuentesC/woe_credit_scoring/blob/master/LICENSE.txt
317 |
318 | [linkedin-shield]: https://img.shields.io/badge/-LinkedIn-black.svg?style=for-the-badge&logo=linkedin&colorB=555
319 |
320 | [linkedin-url]: https://linkedin.com/in/josegustavofuentescabrera
321 |
322 |
323 |
324 |
325 |
--------------------------------------------------------------------------------
/woe_credit_scoring/binning.py:
--------------------------------------------------------------------------------
1 | from typing import Dict, List, Union, Tuple, Optional
2 | from multiprocessing import Pool
3 | from functools import reduce
4 | import numpy as np
5 | import pandas as pd
6 | from sklearn.preprocessing import KBinsDiscretizer
7 | from sklearn.mixture import GaussianMixture
8 | import logging
9 | from .base import WoeBaseFeatureSelector
10 | from .normalizer import DiscreteNormalizer
11 |
12 | logger = logging.getLogger("CreditScoringToolkit")
13 |
14 | class Discretizer:
15 | """
16 | Discretizer class for transforming continuous data into discrete bins.
17 |
18 | This class provides methods to fit a discretization model to continuous data and transform the data into discrete bins.
19 | It supports multiple discretization strategies including 'uniform', 'quantile', 'kmeans', and 'gaussian'.
20 | The class uses parallel processing to speed up the computation when dealing with large datasets.
21 |
22 | Attributes:
23 | min_segments (int): Minimum number of bins to create.
24 | max_segments (int): Maximum number of bins to create.
25 | strategy (str): Discretization strategy to use.
26 | X (pd.DataFrame): The input data used for fitting the model.
27 | features (List[str]): List of feature names in the input data.
28 | edges_map (Dict): Dictionary mapping features to their respective bin edges.
29 | __is_fitted (bool): Flag indicating whether the model has been fitted.
30 |
31 | Methods:
32 | _make_pool(func, params, threads): Executes a function with a set of parameters using pooling threads.
33 | fit(X, n_threads): Learns discretization edges from the input data.
34 | transform(X, n_threads): Transforms continuous data into its discrete form.
35 | _discretize(X, feature, nbins, strategy): Discretizes a series into a specified number of bins using the given strategy.
36 | _encode(X, feature, nbins, edges, strategy): Encodes a continuous feature into a discrete bin.
37 | """
38 |
39 | def __init__(self, min_segments: int = 2, max_segments: int = 5, strategy: str = 'quantile') -> None:
40 | self.__is_fitted = False
41 | self.X = None
42 | self.min_segments = min_segments
43 | self.max_segments = max_segments
44 | self.strategy = strategy
45 | self.features = None
46 | self.edges_map = {}
47 |
48 | @staticmethod
49 | def _make_pool(func, params: List[Tuple], threads: int) -> List:
50 | """
51 | Executes a function with a set of parameters using pooling threads.
52 |
53 | Args:
54 | func (function): Function to be executed.
55 | params (list): List of tuples, each tuple is a parameter combination.
56 | threads (int): Number of pooling threads to use.
57 |
58 | Returns:
59 | list: All execution results in a list.
60 | """
61 | with Pool(threads) as pool:
62 | data = pool.starmap(func, params)
63 | return data
64 |
65 | def fit(self, X: pd.DataFrame, n_threads: int = 1) -> None:
66 | """
67 | Learns discretization edges.
68 |
69 | Args:
70 | X (pd.DataFrame): Data to be discretized.
71 | n_threads (int, optional): Number of pooling threads. Defaults to 1.
72 | """
73 | self.X = X.copy()
74 | self.features = list(self.X.columns)
75 | self.edges_map = self._make_pool(
76 | self._discretize,
77 | [(self.X, feat, nbins, self.strategy) for feat in self.features for nbins in range(
78 | self.min_segments, self.max_segments + 1)],
79 | threads=n_threads
80 | )
81 | self.__is_fitted = True
82 |
83 | @staticmethod
84 | def _discretize(X: pd.DataFrame, feature: str, nbins: int, strategy: str) -> Dict:
85 | """
86 | Discretizes a series in a particular number of bins using the given strategy.
87 |
88 | Args:
89 | X (pd.DataFrame): Data to be discretized.
90 | feature (str): Feature name.
91 | nbins (int): Number of expected bins.
92 | strategy (str): {'uniform', 'quantile', 'kmeans', 'gaussian'}, discretization method to be used.
93 |
94 | Returns:
95 | dict: Discretized data.
96 |
97 | Reference:
98 | For more details on the discretization strategies, see
99 | https://journals.plos.org/plosone/article/authors?id=10.1371/journal.pone.0289130
100 | """
101 | aux = X[[feature]].copy()
102 | has_missing = aux[feature].isnull().any()
103 | if has_missing:
104 | nonmiss = aux.dropna().reset_index(drop=True)
105 | else:
106 | nonmiss = aux.copy()
107 |
108 | if strategy != 'gaussian':
109 | if nonmiss[feature].nunique() > 1:
110 | n_bins = min(nbins, nonmiss[feature].nunique())
111 | kb = KBinsDiscretizer(n_bins=n_bins, encode='ordinal', strategy=strategy)
112 | kb.fit(nonmiss[[feature]])
113 | edges = list(kb.bin_edges_[0])
114 | return {'feature': feature, 'nbins': nbins, 'edges': [-np.inf] + edges[1:-1] + [np.inf]}
115 | else:
116 | edges = [-np.inf, np.inf]
117 | return {'feature': feature, 'nbins': nbins, 'edges': edges}
118 | else:
119 | gm = GaussianMixture(n_components=nbins)
120 | gm.fit(nonmiss[[feature]])
121 | nonmiss['cluster'] = gm.predict(nonmiss[[feature]])
122 | edges = nonmiss.groupby('cluster')[feature].agg(
123 | ['min', 'max']).sort_values(by='min')
124 | edges = sorted(set(edges['min'].tolist() + edges['max'].tolist()))
125 | return {'feature': feature, 'nbins': nbins, 'edges': [-np.inf] + edges[1:-1] + [np.inf]}
126 |
127 | @staticmethod
128 | def _encode(X: pd.DataFrame, feature: str, nbins: int, edges: List[float], strategy: str) -> pd.DataFrame:
129 | """
130 | Encodes continuous feature into a discrete bin.
131 |
132 | Args:
133 | X (pd.DataFrame): Continuous data.
134 | feature (str): Feature to be encoded.
135 | nbins (int): Number of encoding bins.
136 | edges (list): Bin edges list.
137 | strategy (str): {'uniform', 'quantile', 'kmeans', 'gaussian'}, discretization strategy.
138 |
139 | Returns:
140 | pd.DataFrame: Encoded data.
141 | """
142 | aux = pd.cut(X[feature], bins=edges, include_lowest=True)
143 | aux = pd.Series(np.where(aux.isnull(), 'MISSING', aux)
144 | ).to_frame().astype(str)
145 | discretized_feature_name = f'disc_{feature}_{nbins}_{strategy}'
146 | aux.columns = [discretized_feature_name]
147 | return aux
148 |
149 | def transform(self, X: pd.DataFrame, n_threads: int = 1) -> pd.DataFrame:
150 | """
151 | Transforms continuous data into its discrete form.
152 |
153 | Args:
154 | X (pd.DataFrame): Data to be discretized.
155 | n_threads (int, optional): Number of pooling threads to speed computation. Defaults to 1.
156 |
157 | Raises:
158 | Exception: If fit method not called previously.
159 | Exception: If features analyzed during fit are not present in X.
160 |
161 | Returns:
162 | pd.DataFrame: Discretized Data.
163 | """
164 | if not self.__is_fitted:
165 | raise Exception(
166 | 'Please call fit method first with the required parameters')
167 |
168 | aux = X.copy()
169 | features = list(set(edge['feature'] for edge in self.edges_map))
170 | non_present_features = [f for f in features if f not in X.columns]
171 | if non_present_features:
172 | raise Exception(
173 | f"Missing features: {', '.join(non_present_features)}")
174 |
175 | encoded_data = self._make_pool(
176 | self._encode,
177 | [(X, edge_map['feature'], edge_map['nbins'], edge_map['edges'],
178 | self.strategy) for edge_map in self.edges_map],
179 | threads=n_threads
180 | )
181 |
182 | result = reduce(lambda x, y: pd.merge(
183 | x, y, left_index=True, right_index=True, how='inner'), encoded_data).copy()
184 | return result
185 |
186 |
187 | class WoeContinuousFeatureSelector(WoeBaseFeatureSelector):
188 | """
189 | WoeContinuousFeatureSelector is a class for selecting continuous features based on their Weight of Evidence (WoE) transformation and Information Value (IV) statistic.
190 |
191 | This class provides methods to fit a model that evaluates continuous features by discretizing them into bins, transforming them using WoE, and calculating their IV.
192 | It supports multiple discretization strategies including 'quantile', 'uniform', 'kmeans', 'gaussian', 'dcc', and 'dec'.
193 | The class can also enforce monotonic risk behavior for the selected features if required.
194 |
195 | Attributes:
196 | selected_features (Optional[List[Dict[str, Union[str, float]]]]): List of selected features with their respective IV values.
197 | __is_fitted (bool): Flag indicating whether the model has been fitted.
198 | _Xd (Optional[pd.DataFrame]): DataFrame containing the discretized features.
199 | discretizers (Optional[List[Discretizer]]): List of Discretizer objects used for discretizing the features.
200 | iv_report (Optional[pd.DataFrame]): DataFrame containing the IV report for all features.
201 |
202 | Methods:
203 | fit(X, y, method, iv_threshold, min_bins, max_bins, n_threads, strictly_monotonic): Learns the best features given an IV threshold and optional monotonic risk restriction.
204 | transform(X): Converts continuous features to their best discretization.
205 | """
206 | selected_features: Optional[List[Dict[str, Union[str, float]]]] = None
207 | __is_fitted: bool = False
208 | _Xd: Optional[pd.DataFrame] = None
209 | discretizers: Optional[List[Discretizer]] = None
210 | iv_report: Optional[pd.DataFrame] = None
211 |
212 | def __init__(self) -> None:
213 | super().__init__()
214 |
215 | def fit(self, X: pd.DataFrame, y: pd.Series, method: str = 'quantile', iv_threshold: float = 0.1,
216 | min_bins: int = 2, max_bins: int = 5, n_threads: int = 1, strictly_monotonic: bool = False) -> None:
217 | """
218 | Learns the best features given an IV threshold. Monotonic risk restriction can be applied.
219 |
220 | Args:
221 | X (pd.DataFrame): Predictors data.
222 | y (pd.Series): Dichotomic response feature.
223 | method (str, optional): Discretization technique. Options are {'quantile', 'uniform', 'kmeans', 'gaussian', 'dcc', 'dec'}.
224 | Defaults to 'quantile'.
225 | iv_threshold (float, optional): IV value for a feature to be included in final selection. Defaults to 0.1.
226 | min_bins (int, optional): Minimum number of discretization bins. Defaults to 2.
227 | max_bins (int, optional): Maximum number of discretization bins. Defaults to 5.
228 | n_threads (int, optional): Number of multiprocessing threads. Defaults to 1.
229 | strictly_monotonic (bool, optional): Indicates if only monotonic risk features should be selected. Defaults to False.
230 |
231 | Raises:
232 | Exception: If strictly_monotonic=True and no monotonic feature is present in the final selection.
233 | Exception: If method is not in {'quantile', 'uniform', 'kmeans', 'gaussian', 'dcc', 'dec'}.
234 | Exception: If X is not a pandas DataFrame.
235 | Exception: If y is not a pandas Series.
236 |
237 | Reference:
238 | For more information about the dcc and dec methods please refer to the following paper:
239 | https://journals.plos.org/plosone/article/authors?id=10.1371/journal.pone.0289130
240 | """
241 | if not isinstance(X, pd.DataFrame):
242 | raise TypeError('X must be a pandas DataFrame')
243 | if not isinstance(y, pd.Series):
244 | raise TypeError('y must be a pandas Series')
245 |
246 | cont_features = list(X.columns)
247 | methods = ['quantile', 'uniform', 'kmeans', 'gaussian']
248 |
249 | if method not in methods + ['dcc', 'dec']:
250 | raise Exception('Invalid method, options are quantile, uniform, kmeans, gaussian, dcc and dec')
251 |
252 | if method in methods:
253 | discretizers = [Discretizer(strategy=method, min_segments=min_bins, max_segments=max_bins)]
254 | else:
255 | discretizers = [Discretizer(strategy=m, min_segments=min_bins, max_segments=max_bins) for m in methods]
256 |
257 | for disc in discretizers:
258 | disc.fit(X[cont_features], n_threads=n_threads)
259 |
260 | self.discretizers = discretizers
261 | self._Xd = pd.concat([disc.transform(X[cont_features]) for disc in discretizers], axis=1)
262 | disc_features = list(self._Xd.columns)
263 | self._Xd['binary_target'] = y
264 |
265 | if strictly_monotonic:
266 | mono = {feature: self._check_monotonic(self._Xd[feature], self._Xd['binary_target']) for feature in disc_features}
267 | mono = {x: y for x, y in mono.items() if y}
268 | if not mono:
269 | raise Exception('There is no monotonic feature.\n Please try turning strictly_monotonic parameter to False or increase the number of bins')
270 | disc_features = list(mono.keys())
271 |
272 | iv = [(feature, self._information_value(self._Xd[feature], self._Xd['binary_target'])) for feature in disc_features]
273 | self.iv_report = pd.DataFrame(iv, columns=['feature', 'iv']).dropna().reset_index(drop=True)
274 | self.iv_report['relevant'] = self.iv_report['iv'] >= iv_threshold
275 |
276 | self.iv_report['root_feature'] = self.iv_report['feature'].apply(lambda x: "_".join(x.split('_')[1:-2]))
277 | self.iv_report['nbins'] = self.iv_report['feature'].apply(lambda x: x.split('_')[-2])
278 | self.iv_report['method'] = self.iv_report['feature'].apply(lambda x: x.split('_')[-1])
279 |
280 | sort_columns = ['root_feature', 'iv', 'nbins'] if method in methods + ['dcc'] else ['root_feature', 'method', 'iv', 'nbins']
281 | self.iv_report = self.iv_report.sort_values(by=sort_columns, ascending=[True, False, True] if method in methods + ['dcc'] else [True, True, False, True]).reset_index(drop=True)
282 | self.iv_report['index'] = self.iv_report.groupby('root_feature').cumcount() + 1 if method in methods + ['dcc'] else self.iv_report.groupby(['root_feature', 'method']).cumcount() + 1
283 |
284 | self.iv_report = self.iv_report.loc[self.iv_report['index'] == 1].reset_index(drop=True)
285 | self.iv_report['selected'] = self.iv_report['feature'].isin(self.iv_report['feature'])
286 | self.iv_report = self.iv_report.sort_values(by=['selected', 'relevant'], ascending=[False, False])
287 | cont_features = list(set(self.iv_report.loc[self.iv_report['relevant']]['root_feature']))
288 | if len(cont_features) == 0:
289 | raise Exception('No relevant feature found. Please try increasing the number of bins or changing the discretization method')
290 | for disc in self.discretizers:
291 | disc.fit(X[cont_features], n_threads=n_threads)
292 | self.selected_features =self.iv_report[self.iv_report['relevant']].drop('index', axis=1).to_dict(orient='records')
293 | self.__is_fitted = True
294 |
295 | def transform(self, X: pd.DataFrame) -> pd.DataFrame:
296 | """
297 | Converts continuous features to their best discretization.
298 |
299 | Args:
300 | X (pd.DataFrame): Continuous predictors data.
301 |
302 | Raises:
303 | Exception: If fit method is not called first.
304 | Exception: If a fitted feature is not present in data.
305 | Exception: If X is not a pandas DataFrame.
306 |
307 | Returns:
308 | pd.DataFrame: Best discretization transformed data.
309 | """
310 | if not self.__is_fitted:
311 | raise Exception(
312 | 'Please call fit method first with the required parameters')
313 |
314 | if not isinstance(X, pd.DataFrame):
315 | raise TypeError('X must be a pandas DataFrame')
316 |
317 | aux = X.copy()
318 | features = list(set([feature['root_feature']
319 | for feature in self.selected_features]))
320 | non_present_features = [f for f in features if f not in X.columns]
321 |
322 | if non_present_features:
323 | logger.exception(f'{", ".join(non_present_features)} feature{"s" if len(non_present_features) > 1 else ""} not present in data')
324 | raise Exception("Missing features")
325 |
326 | aux = pd.concat([disc.transform(X[features])
327 | for disc in self.discretizers], axis=1)
328 | aux = aux[[feature['feature'] for feature in self.selected_features]]
329 | return aux
330 |
331 |
332 | class WoeDiscreteFeatureSelector(WoeBaseFeatureSelector):
333 | """
334 | WoeDiscreteFeatureSelector is a class for selecting discrete features based on their Weight of Evidence (WoE)
335 | transformation and Information Value (IV) statistic. This class inherits from WoeBaseFeatureSelector and provides
336 | methods to fit the model to the data and transform the data by keeping only the selected features.
337 |
338 | The fit method evaluates each feature's predictive power by calculating its IV and selects features that meet
339 | a specified IV threshold. The transform method then filters the dataset to include only these selected features.
340 |
341 | Attributes:
342 | iv_report (pd.DataFrame): A DataFrame containing the IV values and selection status of each feature.
343 | selected_features (dict[str, float]): A dictionary of selected features and their corresponding IV values.
344 | __is_fitted (bool): A flag indicating whether the fit method has been called.
345 | """
346 | iv_report: pd.DataFrame = None
347 |
348 | def __init__(self) -> None:
349 | super().__init__()
350 |
351 | def fit(self, X: pd.DataFrame, y: pd.Series, iv_threshold: float = 0.1) -> None:
352 | """Learns best features given an IV threshold.
353 |
354 | Args:
355 | X (pd.DataFrame): Discrete predictors data
356 | y (pd.Series): Dichotomic response feature
357 | iv_threshold (float, optional): IV value for a feature to be included in final selection. Defaults to 0.1.
358 | """
359 | disc_features: list[str] = list(X.columns)
360 | aux: pd.DataFrame = X.copy()
361 | aux['binary_target'] = y
362 | iv: list[tuple[str, float]] = [(feature, self._information_value(
363 | aux[feature], aux['binary_target'])) for feature in disc_features]
364 | self.iv_report = pd.DataFrame(iv, columns=['feature', 'iv']).dropna().reset_index(drop=True)
365 | self.iv_report['selected'] = self.iv_report['iv'] >= iv_threshold
366 | self.iv_report = self.iv_report.sort_values('selected', ascending=False)
367 | disc_features = list(self.iv_report.loc[self.iv_report['selected']]['feature'])
368 | if len(disc_features) == 0:
369 | raise Exception(
370 | 'No relevant feature found. Please try increasing the IV threshold')
371 | self.selected_features: dict[str, float] =self.iv_report.loc[self.iv_report['selected']].set_index('feature')[
372 | 'iv'].to_dict()
373 | self.__is_fitted: bool = True
374 |
375 | def transform(self, X: pd.DataFrame) -> pd.DataFrame:
376 | """Transforms data keeping only the selected features
377 |
378 | Args:
379 | X (pd.DataFrame): Discrete predictors data
380 |
381 | Raises:
382 | Exception: If fit method is not called first.
383 | Exception: If a fitted feature is not present in data.
384 |
385 | Returns:
386 | pd.DataFrame: Data containing best discrete features
387 | """
388 | if not self.__is_fitted:
389 | raise Exception(
390 | 'Please call fit method first with the required parameters')
391 | else:
392 | aux: pd.DataFrame = X.copy()
393 | features: list[str] = [
394 | feature for feature in self.selected_features.keys()]
395 | non_present_features: list[str] = [
396 | f for f in features if f not in X.columns]
397 | if len(non_present_features) > 0:
398 | logger.exception(
399 | f'{",".join(non_present_features)} feature{"s" if len(non_present_features) > 1 else ""} not present in data')
400 | raise Exception("Missing features")
401 | else:
402 | aux = aux[features]
403 | return aux
404 |
405 |
406 | class IVCalculator:
407 | """
408 | A class to calculate the Information Value (IV) for both discrete and continuous features.
409 | It provides a simple interface that abstracts away the manual steps of discretization and normalization.
410 |
411 | Example:
412 | >>> from woe_credit_scoring import IVCalculator
413 | >>> import pandas as pd
414 | >>> data = pd.read_csv('example_data/hmeq.csv')
415 | >>> iv_calculator = IVCalculator(
416 | ... data=data,
417 | ... target='BAD',
418 | ... continuous_features=['LOAN', 'MORTDUE', 'VALUE', 'YOJ', 'DEROG', 'DELINQ', 'CLAGE', 'NINQ', 'CLNO', 'DEBTINC'],
419 | ... discrete_features=['REASON', 'JOB']
420 | ... )
421 | >>> iv_report = iv_calculator.calculate_iv()
422 | >>> print(iv_report)
423 |
424 | """
425 | def __init__(self, data: pd.DataFrame, target: str, continuous_features: List[str] = None, discrete_features: List[str] = None):
426 | """
427 | Initializes the IVCalculator object.
428 |
429 | Args:
430 | data (pd.DataFrame): The input data containing features and target.
431 | target (str): The target variable name.
432 | continuous_features (List[str], optional): List of continuous feature names. Defaults to None.
433 | discrete_features (List[str], optional): List of discrete feature names. Defaults to None.
434 | """
435 | if not isinstance(data, pd.DataFrame):
436 | raise TypeError("data must be a pandas DataFrame.")
437 | if target not in data.columns:
438 | raise ValueError(f"Target column '{target}' not found in the DataFrame.")
439 |
440 | self.data = data
441 | self.target = target
442 | self.continuous_features = continuous_features if continuous_features is not None else []
443 | self.discrete_features = discrete_features if discrete_features is not None else []
444 |
445 | if not self.continuous_features and not self.discrete_features:
446 | logger.warning("No continuous or discrete features provided.")
447 |
448 | def calculate_iv(self,
449 | max_discretization_bins: int = 5,
450 | strictly_monotonic: bool = False,
451 | discretization_method: str = 'quantile',
452 | n_threads: int = 1,
453 | discrete_normalization_threshold: float = 0.05,
454 | discrete_normalization_default_category: str = 'OTHER'
455 | ) -> pd.DataFrame:
456 | """
457 | Calculates the Information Value (IV) for the provided features.
458 |
459 | Args:
460 | max_discretization_bins (int, optional): The maximum number of bins for discretization. Defaults to 5.
461 | strictly_monotonic (bool, optional): Whether to enforce strictly monotonic WoE transformation for continuous features. Defaults to False.
462 | discretization_method (str, optional): The method for discretization ('quantile', 'uniform', 'kmeans', 'gaussian', 'dcc', 'dec'). Defaults to 'quantile'.
463 | n_threads (int, optional): The number of threads to use for parallel processing. Defaults to 1.
464 | discrete_normalization_threshold (float, optional): The threshold for discrete feature normalization. Defaults to 0.05.
465 | discrete_normalization_default_category (str, optional): The default category for discrete feature normalization. Defaults to 'OTHER'.
466 |
467 | Returns:
468 | pd.DataFrame: A DataFrame containing the IV report for all features, sorted by IV in descending order.
469 | """
470 | iv_reports = []
471 |
472 | if self.continuous_features:
473 | logger.info("Calculating IV for continuous features...")
474 | woe_continuous_selector = WoeContinuousFeatureSelector()
475 | try:
476 | woe_continuous_selector.fit(
477 | self.data[self.continuous_features],
478 | self.data[self.target],
479 | max_bins=max_discretization_bins,
480 | strictly_monotonic=strictly_monotonic,
481 | iv_threshold=-np.inf, # Using a very low threshold to get IV for all features
482 | method=discretization_method,
483 | n_threads=n_threads
484 | )
485 | iv_report_continuous = woe_continuous_selector.iv_report
486 | iv_report_continuous = iv_report_continuous[['root_feature', 'iv']].rename(columns={'root_feature': 'feature'})
487 | iv_report_continuous['feature_type'] = 'continuous'
488 | iv_reports.append(iv_report_continuous)
489 | logger.info("IV for continuous features calculated successfully.")
490 | except Exception as e:
491 | logger.error(f"Could not calculate IV for continuous features. Error: {e}")
492 |
493 | if self.discrete_features:
494 | logger.info("Calculating IV for discrete features...")
495 | try:
496 | dn = DiscreteNormalizer(
497 | normalization_threshold=discrete_normalization_threshold,
498 | default_category=discrete_normalization_default_category
499 | )
500 | dn.fit(self.data[self.discrete_features])
501 | normalized_discrete_data = dn.transform(self.data[self.discrete_features])
502 |
503 | woe_discrete_selector = WoeDiscreteFeatureSelector()
504 | woe_discrete_selector.fit(
505 | normalized_discrete_data,
506 | self.data[self.target],
507 | iv_threshold=-np.inf # Using a very low threshold to get IV for all features
508 | )
509 | iv_report_discrete = woe_discrete_selector.iv_report[['feature', 'iv']]
510 | iv_report_discrete['feature_type'] = 'discrete'
511 | iv_reports.append(iv_report_discrete)
512 | logger.info("IV for discrete features calculated successfully.")
513 | except Exception as e:
514 | logger.error(f"Could not calculate IV for discrete features. Error: {e}")
515 |
516 | if not iv_reports:
517 | logger.warning("IV calculation did not produce any results.")
518 | return pd.DataFrame(columns=['feature', 'iv', 'feature_type'])
519 |
520 | final_iv_report = pd.concat(iv_reports, axis=0).sort_values('iv', ascending=False).reset_index(drop=True)
521 | return final_iv_report
522 |
--------------------------------------------------------------------------------
/woe_credit_scoring/autocreditscoring.py:
--------------------------------------------------------------------------------
1 | from typing import List, Optional
2 | import numpy as np
3 | import pandas as pd
4 | from scipy.stats.mstats import winsorize
5 | from sklearn.linear_model import LogisticRegression
6 | from sklearn.model_selection import train_test_split
7 | from sklearn.metrics import roc_auc_score, roc_curve, auc
8 | import matplotlib.pyplot as plt
9 | import seaborn as sns
10 | from collections import ChainMap
11 | import os
12 | import logging
13 | from .normalizer import DiscreteNormalizer
14 | from .binning import WoeContinuousFeatureSelector, WoeDiscreteFeatureSelector
15 | from .encoder import WoeEncoder
16 | from .scoring import CreditScoring
17 |
18 | logger = logging.getLogger("CreditScoringToolkit")
19 |
20 | class AutoCreditScoring:
21 | """
22 | A class used to perform automated credit scoring using logistic regression and Weight of Evidence (WoE) transformation.
23 | Attributes
24 | ----------
25 | continuous_features : List[str]
26 | List of continuous feature names.
27 | discrete_features : List[str]
28 | List of discrete feature names.
29 | target : str
30 | The target variable name.
31 | data : pd.DataFrame
32 | The input data containing features and target.
33 | train : pd.DataFrame
34 | The training dataset.
35 | valid : pd.DataFrame
36 | The validation dataset.
37 | apply_multicolinearity : bool, optional
38 | Whether to apply multicollinearity treatment (default is False).
39 | iv_feature_threshold : float, optional
40 | The Information Value (IV) threshold for feature selection (default is 0.05).
41 | treat_outliers : bool, optional
42 | Whether to treat outliers in continuous features (default is False).
43 | outlier_threshold : float, optional
44 | The threshold for outlier treatment (default is 0.01).
45 | min_score : int, optional
46 | The minimum score for the credit scoring model (default is 400).
47 | max_score : int, optional
48 | The maximum score for the credit scoring model (default is 900).
49 | max_discretization_bins : int, optional
50 | The maximum number of bins for discretization (default is 5).
51 | discrete_normalization_threshold : float, optional
52 | The threshold for discrete feature normalization (default is 0.05).
53 | discrete_normalization_default_category : str, optional
54 | The default category for discrete feature normalization (default is 'OTHER').
55 | transformation : Optional[str], optional
56 | The transformation method to be applied (default is None).
57 | model : Optional[LogisticRegression], optional
58 | The logistic regression model (default is None).
59 | max_iter : int, optional
60 | The maximum number of iterations for partitioning data (default is 5).
61 | train_size : float, optional
62 | The proportion of data to be used for training (default is 0.7).
63 | target_proportion_tolerance : float, optional
64 | The tolerance for target proportion difference between train and valid datasets (default is 0.01).
65 | strictly_monotonic : bool, optional
66 | Whether to enforce strictly monotonic WoE transformation (default is True).
67 | discretization_method : str, optional
68 | The method for discretization (default is 'quantile').
69 | n_threads : int, optional
70 | The number of threads to use for parallel processing (default is 1).
71 | overfitting_tolerance : float, optional
72 | The tolerance for overfitting detection (default is 0.01).
73 | create_reporting : bool, optional
74 | Whether to create reporting after model fitting (default is False).
75 | is_fitted : bool, optional
76 | Whether the model has been fitted (default is False).
77 | Methods
78 | -------
79 | __init__(self, data: pd.DataFrame, target: str, continuous_features: List[str]=None, discrete_features: List[str]=None)
80 | Initializes the AutoCreditScoring object with data, target, and feature lists.
81 | fit(self, target_proportion_tolerance: float = None, treat_outliers: bool = None, discrete_normalization_threshold: float = None, discrete_normalization_default_category: str = None, max_discretization_bins: int = None, strictly_monotonic: bool = None, iv_feature_threshold: float = None, discretization_method: str = None, n_threads: int = None, overfitting_tolerance: float = None, min_score: int = None, max_score: int = None, create_reporting: bool = None, verbose: bool = False)
82 | Fits the credit scoring model to the data with optional parameters for customization.
83 | __partition_data(self)
84 | Partitions the data into training and validation sets while ensuring target proportion compatibility.
85 | __outlier_treatment(self)
86 | Applies outlier treatment to continuous features in the training dataset.
87 | __normalize_discrete(self)
88 | Normalizes discrete features in the training dataset.
89 | __feature_selection(self)
90 | Performs feature selection based on Information Value (IV) for continuous and discrete features.
91 | __woe_transformation(self)
92 | Applies Weight of Evidence (WoE) transformation to the selected features.
93 | __apply_pipeline(self, data: pd.DataFrame) -> pd.DataFrame
94 | Applies the entire preprocessing and transformation pipeline to new data.
95 | __train_model(self)
96 | Trains the logistic regression model on the transformed training data.
97 | __scoring(self)
98 | Generates credit scores for the training and validation datasets.
99 | __reporting(self)
100 | Creates various reports and visualizations for model evaluation and interpretation.
101 | save_reports(self, folder: str = '.')
102 | Saves the generated reports and visualizations to the specified folder.
103 | predict(self, X: pd.DataFrame) -> pd.DataFrame
104 | Predicts scores for a given raw dataset.
105 | fit_predict(self, **kwargs) -> pd.DataFrame
106 | Fits the model and returns the scores for the entire dataset.
107 | """
108 | continuous_features: List[str]
109 | discrete_features: List[str]
110 | target: str
111 | data: pd.DataFrame
112 | train: pd.DataFrame
113 | valid: pd.DataFrame
114 | iv_feature_threshold: float = 0.05
115 | treat_outliers: bool = False
116 | outlier_threshold: float = 0.01
117 | min_score = 400
118 | max_score = 900
119 | max_discretization_bins = 5
120 | discrete_normalization_threshold = 0.05
121 | discrete_normalization_default_category = 'OTHER'
122 | transformation: Optional[str] = None
123 | model: Optional[LogisticRegression] = None
124 | max_iter: int = 5
125 | train_size: float = 0.7
126 | target_proportion_tolerance: float = 0.01
127 | max_discretization_bins:int=6
128 | strictly_monotonic:bool=True
129 | discretization_method:str = 'quantile'
130 | n_threads:int = 1
131 | overfitting_tolerance:float = 0.01
132 | create_reporting:bool = False
133 | is_fitted:bool = False
134 |
135 | def __init__(self, data: pd.DataFrame, target: str, continuous_features: List[str]=None, discrete_features: List[str]=None):
136 | self.data = data
137 | self.continuous_features = continuous_features
138 | self.discrete_features = discrete_features
139 | self.target = target
140 |
141 | def fit(self,
142 | target_proportion_tolerance:float = None,
143 | train_proportion:float = None,
144 | treat_outliers:bool = None,
145 | discrete_normalization_threshold:float = None,
146 | discrete_normalization_default_category:str = None,
147 | max_discretization_bins:int = None,
148 | strictly_monotonic:bool = None,
149 | iv_feature_threshold:float = None,
150 | discretization_method:str = None,
151 | n_threads:int = None,
152 | overfitting_tolerance:float = None,
153 | min_score:int = None,
154 | max_score:int = None,
155 | create_reporting:bool = None,
156 | verbose:bool=False):
157 |
158 | #Train proportion control
159 | if train_proportion is not None:
160 | self.train_size = train_proportion
161 |
162 | # Verbosity control
163 | if verbose:
164 | logger.setLevel(logging.INFO)
165 | else:
166 | logger.setLevel(logging.WARNING)
167 | # Check if continuous_features is provided
168 | if self.continuous_features is None:
169 | self.continuous_features = []
170 | logger.warning("No continuous features provided")
171 | # Check if discrete_features is provided
172 | if self.discrete_features is None:
173 | self.discrete_features = []
174 | logger.warning("No discrete features provided")
175 | if len(self.continuous_features)==0 and len(self.discrete_features)==0:
176 | logger.error("No features provided")
177 | raise RuntimeError("No features provided")
178 |
179 | # Check if target_proportion_tolerance is provided
180 | if target_proportion_tolerance is not None:
181 | self.target_proportion_tolerance = target_proportion_tolerance
182 | # Partition data
183 | self.__partition_data()
184 |
185 | #Check if treat_outliers is provided
186 | if len(self.continuous_features)>0 and treat_outliers is not None:
187 | self.treat_outliers = treat_outliers
188 | self.__outlier_treatment()
189 |
190 | # Check if discrete_normalization_threshold is provided
191 | if discrete_normalization_threshold is not None:
192 | self.discrete_normalization_threshold = discrete_normalization_threshold
193 | # Check if discrete_normalization_default_category is provided
194 | if discrete_normalization_default_category is not None:
195 | self.discrete_normalization_default_category = discrete_normalization_default_category
196 | if len(self.discrete_features)==0:
197 | logger.warning("No discrete features provided")
198 | else:
199 | if len(self.discrete_features)>0:
200 | # Normalize discrete features
201 | self.__normalize_discrete()
202 |
203 | #Check feature selection parameters
204 | if max_discretization_bins is not None:
205 | self.max_discretization_bins = max_discretization_bins
206 | if strictly_monotonic is not None:
207 | self.strictly_monotonic = strictly_monotonic
208 | if iv_feature_threshold is not None:
209 | self.iv_feature_threshold = iv_feature_threshold
210 | if discretization_method is not None:
211 | self.discretization_method = discretization_method
212 | if n_threads is not None:
213 | self.n_threads = n_threads
214 |
215 | # Feature selection
216 | self.__feature_selection()
217 |
218 | # Woe transformation
219 | self.__woe_transformation()
220 |
221 | # Check if overfitting_tolerance is provided
222 | if overfitting_tolerance is not None:
223 | self.overfitting_tolerance = overfitting_tolerance
224 | # Train model
225 | self.__train_model()
226 |
227 | # Check if min_score is provided
228 | if min_score is not None:
229 | self.min_score = min_score
230 | # Check if max_score is provided
231 | if max_score is not None :
232 | self.max_score = max_score
233 | # Check if min_score is less than max_score
234 | if self.min_score>=self.max_score:
235 | logger.error("min_score should be less than max_score")
236 | raise RuntimeError("min_score should be less than max_score")
237 | # Scoring
238 | self.__scoring()
239 |
240 | # Check if create_reporting is provided
241 | if create_reporting is not None:
242 | self.create_reporting = create_reporting
243 | # Reporting
244 | if self.create_reporting:
245 | self.__reporting()
246 | self.is_fitted = True
247 |
248 | def predict(self, X: pd.DataFrame) -> pd.DataFrame:
249 | """
250 | Predicts scores for a given raw dataset.
251 |
252 | The input data should have the same features as the training data.
253 | The method applies the same pipeline of transformations as used during training.
254 |
255 | Args:
256 | X (pd.DataFrame): Raw data to be scored.
257 |
258 | Returns:
259 | pd.DataFrame: A DataFrame with scores and feature contributions.
260 |
261 | Raises:
262 | Exception: If the model is not fitted yet.
263 | ValueError: If the input data is missing required features.
264 | """
265 | if not self.is_fitted:
266 | raise Exception("This AutoCreditScoring instance is not fitted yet. Call 'fit' with appropriate arguments before using this method.")
267 |
268 | required_features = self.continuous_features + self.discrete_features
269 | missing_features = [f for f in required_features if f not in X.columns]
270 | if missing_features:
271 | raise ValueError(f"The following required columns are missing from the input data: {', '.join(missing_features)}")
272 |
273 | aux = X.copy()
274 |
275 | # Apply the full pipeline
276 | data_woe = self.__apply_pipeline(aux)
277 |
278 | # Inverse transform to get discrete bins
279 | data_discrete_binned = self.woe_encoder.inverse_transform(data_woe)
280 |
281 | # Get scores
282 | scored_data = self.credit_scoring.transform(data_discrete_binned)
283 |
284 | rename_dict = {
285 | binned_name: f"pts_{original_name}"
286 | for binned_name, original_name in self.feature_name_mapping.items()
287 | if binned_name in scored_data.columns
288 | }
289 | scored_data.rename(columns=rename_dict, inplace=True)
290 |
291 | scored_data['score'] = scored_data['score'].astype(float)
292 |
293 | # Clip scores to the defined range
294 | scored_data['score'] = scored_data['score'].clip(self.min_score, self.max_score)
295 |
296 | # Add score ranges
297 | for k in [5, 10]:
298 | step = (self.max_score - self.min_score) / k
299 | bins = np.arange(self.min_score, self.max_score + step, step)
300 | scored_data[f'range_score_{k}'] = pd.cut(scored_data['score'], bins=bins, include_lowest=True)
301 |
302 | return scored_data
303 |
304 | def __partition_data(self):
305 | logger.info("Partitioning data...")
306 | self.train, self.valid = train_test_split(self.data, train_size=self.train_size)
307 | self.train.reset_index(drop=True, inplace=True)
308 | self.valid.reset_index(drop=True, inplace=True)
309 | # Check if target proportions are compatible between train and valid
310 | logger.info("Checking partition proportions...")
311 | iter = 1
312 | while(np.abs(self.train[self.target].mean()-self.valid[self.target].mean())>self.target_proportion_tolerance):
313 | logger.info(f"Partitioning data...Iteration {iter}")
314 | logger.info(f"Train target proportion: {self.train[self.target].mean()}")
315 | logger.info(f"Valid target proportion: {self.valid[self.target].mean()}")
316 | self.train, self.valid = train_test_split(self.data, train_size=self.train_size)
317 | self.train.reset_index(drop=True, inplace=True)
318 | self.valid.reset_index(drop=True, inplace=True)
319 | iter+=1
320 | if iter>self.max_iter:
321 | logger.error("Could not find a compatible partition")
322 | raise RuntimeError("Could not find a compatible partition")
323 |
324 | if iter>1:
325 | logger.info(f"Partitioning data...Done after {iter} iterations")
326 | logger.info(f"Train shape: {self.train.shape}", )
327 | logger.info(f"Test shape: {self.valid.shape}")
328 | logger.info(f"Train target proportion: {self.train[self.target].mean()}")
329 | logger.info(f"Valid target proportion: {self.valid[self.target].mean()}")
330 |
331 | def __outlier_treatment(self):
332 | logger.info("Outlier treatment...")
333 | before = self.train[self.continuous_features].mean()
334 | for f in self.continuous_features:
335 | self.train[f] = winsorize(self.train[f], limits=[self.outlier_threshold, self.outlier_threshold])
336 | after = self.train[self.continuous_features].mean()
337 | report = pd.DataFrame({'Before':before,'After':after})
338 | logger.info("Mean statistics before and after outlier treatment")
339 | logger.info(f'\n\n{report}\n')
340 | logger.info("Outlier treatment...Done")
341 |
342 | def __normalize_discrete(self):
343 | logger.info("Discrete normalization...")
344 | logger.info(f"Discrete features: {self.discrete_features}")
345 | dn = DiscreteNormalizer(normalization_threshold=self.discrete_normalization_threshold,
346 | default_category=self.discrete_normalization_default_category)
347 | dn.fit(self.train[self.discrete_features])
348 | self.train_discrete_normalized = dn.transform(self.train[self.discrete_features])
349 | logger.info("Checking if normalization produced unary columns")
350 | self.unary_columns = [c for c in self.train_discrete_normalized.columns if self.train_discrete_normalized[c].nunique()==1]
351 | if len(self.unary_columns)>0:
352 | logger.warning(f"Normalization produced unary columns: {self.unary_columns}")
353 | logger.warning(f"Removing unary columns from discrete features")
354 | self.discrete_features = [f for f in self.discrete_features if f not in self.unary_columns]
355 | logger.warning(f"Discrete features after unary columns removal: {self.discrete_features}")
356 | else:
357 | logger.info("No unary columns produced by normalization")
358 | if len(self.discrete_features)==0:
359 | logger.warning("No discrete features left after normalization")
360 | else:
361 | dn.fit(self.train[self.discrete_features])
362 | self.train_discrete_normalized = dn.transform(self.train[self.discrete_features])
363 | self.discrete_normalizer = dn
364 | logger.info("Discrete normalization...Done")
365 |
366 | def __feature_selection(self):
367 | try:
368 | logger.info("Feature selection...")
369 | if len(self.continuous_features)>0:
370 | logger.info("Continuous features selection...")
371 | woe_continuous_selector = WoeContinuousFeatureSelector()
372 | woe_continuous_selector.fit(self.train[self.continuous_features], self.train[self.target],
373 | max_bins=self.max_discretization_bins,
374 | strictly_monotonic=self.strictly_monotonic,
375 | iv_threshold=self.iv_feature_threshold,
376 | method=self.discretization_method,
377 | n_threads=self.n_threads)
378 | self.iv_report_continuous = pd.DataFrame(woe_continuous_selector.selected_features)
379 | self.full_iv_report_continuous = woe_continuous_selector.iv_report.copy()
380 | self.continuous_candidate = woe_continuous_selector.transform(self.train[self.continuous_features])
381 | logger.info(f'\n\n{self.iv_report_continuous}\n\n')
382 | self.woe_continuous_selector = woe_continuous_selector
383 | logger.info(f"Continuous features selection...Done")
384 | if len(self.discrete_features)>0:
385 | logger.info("Discrete features selection...")
386 | woe_discrete_selector = WoeDiscreteFeatureSelector()
387 | woe_discrete_selector.fit(self.train_discrete_normalized, self.train[self.target],self.iv_feature_threshold)
388 | self.iv_report_discrete = pd.Series(woe_discrete_selector.selected_features).to_frame('iv').reset_index().rename(columns={'index':'feature'}).sort_values('iv',ascending=False)
389 | self.full_iv_report_discrete = woe_discrete_selector.iv_report.copy()
390 | self.discrete_candidate = woe_discrete_selector.transform(self.train_discrete_normalized)
391 | logger.info(f'\n\n{self.iv_report_discrete}\n\n')
392 | self.woe_discrete_selector = woe_discrete_selector
393 | logger.info("Discrete features selection...Done")
394 |
395 | if len(self.continuous_features)>0 and len(self.discrete_features)>0:
396 | logger.info("Merging continuous and discrete features...")
397 | self.train_candidate = pd.concat([self.continuous_candidate, self.discrete_candidate], axis=1)
398 | logger.info("Merging continuous and discrete features...Done")
399 | elif len(self.continuous_features)>0:
400 | self.train_candidate = self.continuous_candidate
401 | elif len(self.discrete_features)>0:
402 | self.train_candidate = self.discrete_candidate
403 | self.candidate_features = list(self.train_candidate.columns)
404 | if len(self.candidate_features)==0:
405 | logger.error("No features selected")
406 | raise RuntimeError("No features selected")
407 | logger.info(f"Selected features ({len(self.candidate_features)}): {self.candidate_features}")
408 |
409 | self.feature_name_mapping = {}
410 | if len(self.continuous_features)>0 and hasattr(self, 'iv_report_continuous'):
411 | self.feature_name_mapping.update(self.iv_report_continuous.set_index('feature')['root_feature'].to_dict())
412 |
413 | if len(self.discrete_features)>0 and hasattr(self, 'woe_discrete_selector') and self.woe_discrete_selector.selected_features:
414 | self.feature_name_mapping.update({f: f for f in self.woe_discrete_selector.selected_features.keys()})
415 |
416 | logger.info("Feature selection...Done")
417 | except Exception as err:
418 | logger.error(f"Error in feature selection: {err}")
419 | raise err
420 |
421 | def __woe_transformation(self):
422 | self.woe_encoder = WoeEncoder()
423 | self.woe_encoder.fit(self.train_candidate, self.train[self.target])
424 | self.train_woe = self.woe_encoder.transform(self.train_candidate)
425 | if self.train_woe.isna().max().max():
426 | logger.error("NAs found in transformed data")
427 | raise RuntimeError("NAs found in transformed data, Maybe tiny missing in continuous?")
428 |
429 | def __apply_pipeline(self,data:pd.DataFrame)->pd.DataFrame:
430 | try:
431 | if len(self.continuous_features)>0:
432 | if self.treat_outliers:
433 | for f in self.continuous_features:
434 | data[f] = winsorize(data[f], limits=[self.outlier_threshold, self.outlier_threshold])
435 | data_continuous_candidate = self.woe_continuous_selector.transform(data[self.continuous_features])
436 | if len(self.discrete_features)>0:
437 | data_discrete_normalized = self.discrete_normalizer.transform(data[self.discrete_features])
438 | data_discrete_candidate = self.woe_discrete_selector.transform(data_discrete_normalized)
439 | if len(self.continuous_features)>0 and len(self.discrete_features)==0:
440 | data_candidate = data_continuous_candidate.copy()
441 | if len(self.continuous_features)==0 and len(self.discrete_features)>0:
442 | data_candidate = data_discrete_candidate.copy()
443 | if len(self.continuous_features)>0 and len(self.discrete_features)>0:
444 | data_candidate = pd.concat([data_continuous_candidate, data_discrete_candidate], axis=1)
445 | data_woe = self.woe_encoder.transform(data_candidate)
446 | if data_woe.isna().max().max():
447 | logger.error("NAs found in transformed data")
448 | raise RuntimeError("NAs found in transformed data, Maybe tiny missing in continuous?")
449 | return data_woe
450 | except Exception as err:
451 | logger.error(f"Error applying pipeline: {err}")
452 | raise err
453 |
454 | def __train_model(self):
455 | logger.info("Training model...")
456 | lr = LogisticRegression()
457 | lr.fit(self.train_woe,self.train[self.target])
458 | self.model = lr
459 | self.valid_woe = self.__apply_pipeline(self.valid)
460 | self.auc_train = roc_auc_score(y_score=lr.predict_proba(self.train_woe)[:,1],y_true=self.train[self.target])
461 | self.auc_valid = roc_auc_score(y_score=lr.predict_proba(self.valid_woe)[:,1],y_true=self.valid[self.target])
462 | logger.info(f"AUC for training: {self.auc_train}")
463 | logger.info(f"AUC for validation:{self.auc_valid}")
464 | self.betas = lr.coef_[0]
465 | self.alpha = lr.intercept_[0]
466 | if any([np.abs(b)<0.0001 for b in self.betas]):
467 | logger.warning("Some betas are close to zero, consider removing features")
468 | logger.warning(f"Betas: {dict(zip(self.candidate_features,self.betas))}")
469 | logger.warning(f"Suspicious features: {[f for f,b in zip(self.candidate_features,self.betas) if np.abs(b)<0.0001]}")
470 | if abs(self.auc_train-self.auc_valid)>self.overfitting_tolerance:
471 | logger.warning(f"Overfitting detected, review your hyperparameters. train_auc: {self.auc_train}, valid_auc: {self.auc_valid}")
472 | self.logistic_model = lr
473 | logger.info("Training model...Done")
474 |
475 | def __scoring(self):
476 | logger.info("Scoring...")
477 | cs = CreditScoring()
478 | cs.fit(self.train_woe, self.woe_encoder, self.logistic_model)
479 | self.credit_scoring = cs
480 |
481 | # Get original scores to find min/max for scaling
482 | scored_train_orig = self.credit_scoring.transform(self.woe_encoder.inverse_transform(self.train_woe))
483 | scored_valid_orig = self.credit_scoring.transform(self.woe_encoder.inverse_transform(self.valid_woe))
484 |
485 | self.min_output_score = min(scored_train_orig['score'].min(), scored_valid_orig['score'].min())
486 | self.max_output_score = max(scored_train_orig['score'].max(), scored_valid_orig['score'].max())
487 |
488 | logger.info(f"Min output score: {self.min_output_score}")
489 | logger.info(f"Max output score: {self.max_output_score}")
490 | logger.info(f"Linear transformation to a {self.min_score}-{self.max_score} scale")
491 |
492 | n = self.credit_scoring.n
493 |
494 | if self.max_output_score == self.min_output_score:
495 | logger.warning("All scores are the same, cannot apply linear transformation. Setting all scores to the average of min_score and max_score.")
496 | avg_score = (self.min_score + self.max_score) / 2
497 | self.credit_scoring.scorecard['points'] = np.floor(avg_score / n).astype(int)
498 | else:
499 | # Scaling parameters
500 | a = (self.max_score - self.min_score) / (self.max_output_score - self.min_output_score)
501 | b = self.min_score - a * self.min_output_score
502 | # Update scorecard points
503 | self.credit_scoring.scorecard['points'] = np.floor(a * self.credit_scoring.scorecard['points'] + b / n).astype(int)
504 |
505 | # Update scoring_map from the updated scorecard
506 | self.credit_scoring.scoring_map = dict(ChainMap(*[{f: d[['attribute', 'points']].set_index('attribute')['points'].to_dict()} for f, d in self.credit_scoring.scorecard.reset_index().groupby('feature')]))
507 |
508 | # Recalculate scores with the updated scorecard
509 | self.scored_train = self.credit_scoring.transform(self.woe_encoder.inverse_transform(self.train_woe))
510 | self.scored_valid = self.credit_scoring.transform(self.woe_encoder.inverse_transform(self.valid_woe))
511 |
512 | self.scored_train['score'] = self.scored_train['score'].astype(float)
513 | self.scored_valid['score'] = self.scored_valid['score'].astype(float)
514 |
515 | self.scored_train['score'] = self.scored_train['score'].clip(self.min_score, self.max_score)
516 | self.scored_valid['score'] = self.scored_valid['score'].clip(self.min_score, self.max_score)
517 |
518 | logger.info(f'Transformed min score: {self.scored_train["score"].min()}')
519 | logger.info(f'Transformed max score: {self.scored_train["score"].max()}')
520 |
521 | for k in [5,10]:
522 | step = (self.max_score-self.min_score)/k
523 | bins = np.arange(self.min_score, self.max_score+step, step)
524 | self.scored_train[f'range_score_{k}'] = pd.cut(self.scored_train['score'],bins=bins,include_lowest=True)
525 | self.scored_valid[f'range_score_{k}'] = pd.cut(self.scored_valid['score'],bins=bins,include_lowest=True)
526 | logger.info("Scoring...Done")
527 |
528 | def __reporting(self):
529 | logger.info("Reporting...")
530 | # Distribution images
531 | logger.info("Score Distribution images...")
532 | fig, ax = plt.subplots()
533 | sns.histplot(self.scored_train['score'], kde=False, stat='density', ax=ax, label='Train')
534 | sns.histplot(self.scored_valid['score'], kde=False, stat='density', ax=ax, label='Valid')
535 | ax.set_title("Score histogram")
536 | ax.legend()
537 | self.score_histogram_fig = fig
538 |
539 | fig, ax = plt.subplots()
540 | sns.kdeplot(self.scored_train['score'], ax=ax, label='Train')
541 | sns.kdeplot(self.scored_valid['score'], ax=ax, label='Valid')
542 | ax.set_title("Score KDE")
543 | ax.legend()
544 | self.score_kde_fig = fig
545 | # Event rate images
546 | logger.info("Event rate images...")
547 | self.event_rate_figs = []
548 | for k in [5,10]:
549 | fig, ax = plt.subplots()
550 | ax = pd.crosstab(self.scored_train[f'range_score_{k}'], self.train[self.target], normalize='index').plot(kind='bar', stacked=True, ax=ax)
551 | ax.set_title(f"Event rate by score range ({k} bins)")
552 | setattr(self,f'event_rate_fig_{k}',fig)
553 | self.event_rate_figs.append(fig)
554 | # IV report
555 | logger.info("IV report...")
556 | iv_reports = []
557 | if hasattr(self, 'iv_report_continuous'):
558 | iv_reports.append(self.iv_report_continuous[['root_feature','iv']].rename(columns={'root_feature':'feature'}))
559 | if hasattr(self, 'iv_report_discrete'):
560 | iv_reports.append(self.iv_report_discrete[['feature','iv']])
561 |
562 | if iv_reports:
563 | self.iv_report = pd.concat(iv_reports, axis=0).sort_values('iv', ascending=False)
564 | fig, ax = plt.subplots()
565 | sns.barplot(data=self.iv_report, x='iv', y='feature', ax=ax)
566 | ax.set_title("IV report")
567 | else:
568 | self.iv_report = pd.DataFrame(columns=['feature', 'iv'])
569 | fig, ax = plt.subplots()
570 | ax.text(0.5, 0.5, "No IV report generated.", horizontalalignment='center', verticalalignment='center')
571 | ax.set_title("IV report")
572 | self.iv_report_fig = fig
573 | # ROC Curve
574 | logger.info("ROC Curve...")
575 | fpr_train, tpr_train, _ = roc_curve(self.train[self.target], self.model.predict_proba(self.train_woe)[:, 1])
576 | fpr_valid, tpr_valid, _ = roc_curve(self.valid[self.target], self.model.predict_proba(self.valid_woe)[:, 1])
577 | roc_auc_train = auc(fpr_train, tpr_train)
578 | roc_auc_valid = auc(fpr_valid, tpr_valid)
579 | fig, ax = plt.subplots()
580 | ax.plot(fpr_train, tpr_train, color='blue', lw=2, label=f'Train ROC curve (area = {roc_auc_train:.2f})')
581 | ax.plot(fpr_valid, tpr_valid, color='red', lw=2, label=f'Valid ROC curve (area = {roc_auc_valid:.2f})')
582 | ax.plot([0, 1], [0, 1], color='grey', lw=2, linestyle='--')
583 | ax.set_xlim([0.0, 1.0])
584 | ax.set_ylim([0.0, 1.05])
585 | ax.set_xlabel('False Positive Rate')
586 | ax.set_ylabel('True Positive Rate')
587 | ax.set_title('Receiver Operating Characteristic')
588 | ax.legend(loc="lower right")
589 | self.roc_curve_fig = fig
590 | logger.info("ROC Curve...Done")
591 |
592 | def save_reports(self,folder='.'):
593 | if not self.create_reporting:
594 | raise RuntimeError("Reports were not generated. Please run fit() with create_reporting=True before saving reports.")
595 |
596 | if not os.path.exists(folder):
597 | os.makedirs(folder)
598 | self.score_histogram_fig.savefig(f'{folder}/score_histogram.png')
599 | self.score_kde_fig.savefig(f'{folder}/score_kde.png')
600 | self.iv_report_fig.savefig(f'{folder}/iv_report.png')
601 | for k in [5,10]:
602 | getattr(self,f'event_rate_fig_{k}').savefig(f'{folder}/event_rate_{k}.png')
603 | self.roc_curve_fig.savefig(f'{folder}/roc_curve.png')
604 | logger.info(f"Reports saved in {folder}")
605 |
--------------------------------------------------------------------------------
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275 | d) Convey the object code by offering access from a designated
276 | place (gratis or for a charge), and offer equivalent access to the
277 | Corresponding Source in the same way through the same place at no
278 | further charge. You need not require recipients to copy the
279 | Corresponding Source along with the object code. If the place to
280 | copy the object code is a network server, the Corresponding Source
281 | may be on a different server (operated by you or a third party)
282 | that supports equivalent copying facilities, provided you maintain
283 | clear directions next to the object code saying where to find the
284 | Corresponding Source. Regardless of what server hosts the
285 | Corresponding Source, you remain obligated to ensure that it is
286 | available for as long as needed to satisfy these requirements.
287 |
288 | e) Convey the object code using peer-to-peer transmission, provided
289 | you inform other peers where the object code and Corresponding
290 | Source of the work are being offered to the general public at no
291 | charge under subsection 6d.
292 |
293 | A separable portion of the object code, whose source code is excluded
294 | from the Corresponding Source as a System Library, need not be
295 | included in conveying the object code work.
296 |
297 | A "User Product" is either (1) a "consumer product", which means any
298 | tangible personal property which is normally used for personal, family,
299 | or household purposes, or (2) anything designed or sold for incorporation
300 | into a dwelling. In determining whether a product is a consumer product,
301 | doubtful cases shall be resolved in favor of coverage. For a particular
302 | product received by a particular user, "normally used" refers to a
303 | typical or common use of that class of product, regardless of the status
304 | of the particular user or of the way in which the particular user
305 | actually uses, or expects or is expected to use, the product. A product
306 | is a consumer product regardless of whether the product has substantial
307 | commercial, industrial or non-consumer uses, unless such uses represent
308 | the only significant mode of use of the product.
309 |
310 | "Installation Information" for a User Product means any methods,
311 | procedures, authorization keys, or other information required to install
312 | and execute modified versions of a covered work in that User Product from
313 | a modified version of its Corresponding Source. The information must
314 | suffice to ensure that the continued functioning of the modified object
315 | code is in no case prevented or interfered with solely because
316 | modification has been made.
317 |
318 | If you convey an object code work under this section in, or with, or
319 | specifically for use in, a User Product, and the conveying occurs as
320 | part of a transaction in which the right of possession and use of the
321 | User Product is transferred to the recipient in perpetuity or for a
322 | fixed term (regardless of how the transaction is characterized), the
323 | Corresponding Source conveyed under this section must be accompanied
324 | by the Installation Information. But this requirement does not apply
325 | if neither you nor any third party retains the ability to install
326 | modified object code on the User Product (for example, the work has
327 | been installed in ROM).
328 |
329 | The requirement to provide Installation Information does not include a
330 | requirement to continue to provide support service, warranty, or updates
331 | for a work that has been modified or installed by the recipient, or for
332 | the User Product in which it has been modified or installed. Access to a
333 | network may be denied when the modification itself materially and
334 | adversely affects the operation of the network or violates the rules and
335 | protocols for communication across the network.
336 |
337 | Corresponding Source conveyed, and Installation Information provided,
338 | in accord with this section must be in a format that is publicly
339 | documented (and with an implementation available to the public in
340 | source code form), and must require no special password or key for
341 | unpacking, reading or copying.
342 |
343 | 7. Additional Terms.
344 |
345 | "Additional permissions" are terms that supplement the terms of this
346 | License by making exceptions from one or more of its conditions.
347 | Additional permissions that are applicable to the entire Program shall
348 | be treated as though they were included in this License, to the extent
349 | that they are valid under applicable law. If additional permissions
350 | apply only to part of the Program, that part may be used separately
351 | under those permissions, but the entire Program remains governed by
352 | this License without regard to the additional permissions.
353 |
354 | When you convey a copy of a covered work, you may at your option
355 | remove any additional permissions from that copy, or from any part of
356 | it. (Additional permissions may be written to require their own
357 | removal in certain cases when you modify the work.) You may place
358 | additional permissions on material, added by you to a covered work,
359 | for which you have or can give appropriate copyright permission.
360 |
361 | Notwithstanding any other provision of this License, for material you
362 | add to a covered work, you may (if authorized by the copyright holders of
363 | that material) supplement the terms of this License with terms:
364 |
365 | a) Disclaiming warranty or limiting liability differently from the
366 | terms of sections 15 and 16 of this License; or
367 |
368 | b) Requiring preservation of specified reasonable legal notices or
369 | author attributions in that material or in the Appropriate Legal
370 | Notices displayed by works containing it; or
371 |
372 | c) Prohibiting misrepresentation of the origin of that material, or
373 | requiring that modified versions of such material be marked in
374 | reasonable ways as different from the original version; or
375 |
376 | d) Limiting the use for publicity purposes of names of licensors or
377 | authors of the material; or
378 |
379 | e) Declining to grant rights under trademark law for use of some
380 | trade names, trademarks, or service marks; or
381 |
382 | f) Requiring indemnification of licensors and authors of that
383 | material by anyone who conveys the material (or modified versions of
384 | it) with contractual assumptions of liability to the recipient, for
385 | any liability that these contractual assumptions directly impose on
386 | those licensors and authors.
387 |
388 | All other non-permissive additional terms are considered "further
389 | restrictions" within the meaning of section 10. If the Program as you
390 | received it, or any part of it, contains a notice stating that it is
391 | governed by this License along with a term that is a further
392 | restriction, you may remove that term. If a license document contains
393 | a further restriction but permits relicensing or conveying under this
394 | License, you may add to a covered work material governed by the terms
395 | of that license document, provided that the further restriction does
396 | not survive such relicensing or conveying.
397 |
398 | If you add terms to a covered work in accord with this section, you
399 | must place, in the relevant source files, a statement of the
400 | additional terms that apply to those files, or a notice indicating
401 | where to find the applicable terms.
402 |
403 | Additional terms, permissive or non-permissive, may be stated in the
404 | form of a separately written license, or stated as exceptions;
405 | the above requirements apply either way.
406 |
407 | 8. Termination.
408 |
409 | You may not propagate or modify a covered work except as expressly
410 | provided under this License. Any attempt otherwise to propagate or
411 | modify it is void, and will automatically terminate your rights under
412 | this License (including any patent licenses granted under the third
413 | paragraph of section 11).
414 |
415 | However, if you cease all violation of this License, then your
416 | license from a particular copyright holder is reinstated (a)
417 | provisionally, unless and until the copyright holder explicitly and
418 | finally terminates your license, and (b) permanently, if the copyright
419 | holder fails to notify you of the violation by some reasonable means
420 | prior to 60 days after the cessation.
421 |
422 | Moreover, your license from a particular copyright holder is
423 | reinstated permanently if the copyright holder notifies you of the
424 | violation by some reasonable means, this is the first time you have
425 | received notice of violation of this License (for any work) from that
426 | copyright holder, and you cure the violation prior to 30 days after
427 | your receipt of the notice.
428 |
429 | Termination of your rights under this section does not terminate the
430 | licenses of parties who have received copies or rights from you under
431 | this License. If your rights have been terminated and not permanently
432 | reinstated, you do not qualify to receive new licenses for the same
433 | material under section 10.
434 |
435 | 9. Acceptance Not Required for Having Copies.
436 |
437 | You are not required to accept this License in order to receive or
438 | run a copy of the Program. Ancillary propagation of a covered work
439 | occurring solely as a consequence of using peer-to-peer transmission
440 | to receive a copy likewise does not require acceptance. However,
441 | nothing other than this License grants you permission to propagate or
442 | modify any covered work. These actions infringe copyright if you do
443 | not accept this License. Therefore, by modifying or propagating a
444 | covered work, you indicate your acceptance of this License to do so.
445 |
446 | 10. Automatic Licensing of Downstream Recipients.
447 |
448 | Each time you convey a covered work, the recipient automatically
449 | receives a license from the original licensors, to run, modify and
450 | propagate that work, subject to this License. You are not responsible
451 | for enforcing compliance by third parties with this License.
452 |
453 | An "entity transaction" is a transaction transferring control of an
454 | organization, or substantially all assets of one, or subdividing an
455 | organization, or merging organizations. If propagation of a covered
456 | work results from an entity transaction, each party to that
457 | transaction who receives a copy of the work also receives whatever
458 | licenses to the work the party's predecessor in interest had or could
459 | give under the previous paragraph, plus a right to possession of the
460 | Corresponding Source of the work from the predecessor in interest, if
461 | the predecessor has it or can get it with reasonable efforts.
462 |
463 | You may not impose any further restrictions on the exercise of the
464 | rights granted or affirmed under this License. For example, you may
465 | not impose a license fee, royalty, or other charge for exercise of
466 | rights granted under this License, and you may not initiate litigation
467 | (including a cross-claim or counterclaim in a lawsuit) alleging that
468 | any patent claim is infringed by making, using, selling, offering for
469 | sale, or importing the Program or any portion of it.
470 |
471 | 11. Patents.
472 |
473 | A "contributor" is a copyright holder who authorizes use under this
474 | License of the Program or a work on which the Program is based. The
475 | work thus licensed is called the contributor's "contributor version".
476 |
477 | A contributor's "essential patent claims" are all patent claims
478 | owned or controlled by the contributor, whether already acquired or
479 | hereafter acquired, that would be infringed by some manner, permitted
480 | by this License, of making, using, or selling its contributor version,
481 | but do not include claims that would be infringed only as a
482 | consequence of further modification of the contributor version. For
483 | purposes of this definition, "control" includes the right to grant
484 | patent sublicenses in a manner consistent with the requirements of
485 | this License.
486 |
487 | Each contributor grants you a non-exclusive, worldwide, royalty-free
488 | patent license under the contributor's essential patent claims, to
489 | make, use, sell, offer for sale, import and otherwise run, modify and
490 | propagate the contents of its contributor version.
491 |
492 | In the following three paragraphs, a "patent license" is any express
493 | agreement or commitment, however denominated, not to enforce a patent
494 | (such as an express permission to practice a patent or covenant not to
495 | sue for patent infringement). To "grant" such a patent license to a
496 | party means to make such an agreement or commitment not to enforce a
497 | patent against the party.
498 |
499 | If you convey a covered work, knowingly relying on a patent license,
500 | and the Corresponding Source of the work is not available for anyone
501 | to copy, free of charge and under the terms of this License, through a
502 | publicly available network server or other readily accessible means,
503 | then you must either (1) cause the Corresponding Source to be so
504 | available, or (2) arrange to deprive yourself of the benefit of the
505 | patent license for this particular work, or (3) arrange, in a manner
506 | consistent with the requirements of this License, to extend the patent
507 | license to downstream recipients. "Knowingly relying" means you have
508 | actual knowledge that, but for the patent license, your conveying the
509 | covered work in a country, or your recipient's use of the covered work
510 | in a country, would infringe one or more identifiable patents in that
511 | country that you have reason to believe are valid.
512 |
513 | If, pursuant to or in connection with a single transaction or
514 | arrangement, you convey, or propagate by procuring conveyance of, a
515 | covered work, and grant a patent license to some of the parties
516 | receiving the covered work authorizing them to use, propagate, modify
517 | or convey a specific copy of the covered work, then the patent license
518 | you grant is automatically extended to all recipients of the covered
519 | work and works based on it.
520 |
521 | A patent license is "discriminatory" if it does not include within
522 | the scope of its coverage, prohibits the exercise of, or is
523 | conditioned on the non-exercise of one or more of the rights that are
524 | specifically granted under this License. You may not convey a covered
525 | work if you are a party to an arrangement with a third party that is
526 | in the business of distributing software, under which you make payment
527 | to the third party based on the extent of your activity of conveying
528 | the work, and under which the third party grants, to any of the
529 | parties who would receive the covered work from you, a discriminatory
530 | patent license (a) in connection with copies of the covered work
531 | conveyed by you (or copies made from those copies), or (b) primarily
532 | for and in connection with specific products or compilations that
533 | contain the covered work, unless you entered into that arrangement,
534 | or that patent license was granted, prior to 28 March 2007.
535 |
536 | Nothing in this License shall be construed as excluding or limiting
537 | any implied license or other defenses to infringement that may
538 | otherwise be available to you under applicable patent law.
539 |
540 | 12. No Surrender of Others' Freedom.
541 |
542 | If conditions are imposed on you (whether by court order, agreement or
543 | otherwise) that contradict the conditions of this License, they do not
544 | excuse you from the conditions of this License. If you cannot convey a
545 | covered work so as to satisfy simultaneously your obligations under this
546 | License and any other pertinent obligations, then as a consequence you may
547 | not convey it at all. For example, if you agree to terms that obligate you
548 | to collect a royalty for further conveying from those to whom you convey
549 | the Program, the only way you could satisfy both those terms and this
550 | License would be to refrain entirely from conveying the Program.
551 |
552 | 13. Use with the GNU Affero General Public License.
553 |
554 | Notwithstanding any other provision of this License, you have
555 | permission to link or combine any covered work with a work licensed
556 | under version 3 of the GNU Affero General Public License into a single
557 | combined work, and to convey the resulting work. The terms of this
558 | License will continue to apply to the part which is the covered work,
559 | but the special requirements of the GNU Affero General Public License,
560 | section 13, concerning interaction through a network will apply to the
561 | combination as such.
562 |
563 | 14. Revised Versions of this License.
564 |
565 | The Free Software Foundation may publish revised and/or new versions of
566 | the GNU General Public License from time to time. Such new versions will
567 | be similar in spirit to the present version, but may differ in detail to
568 | address new problems or concerns.
569 |
570 | Each version is given a distinguishing version number. If the
571 | Program specifies that a certain numbered version of the GNU General
572 | Public License "or any later version" applies to it, you have the
573 | option of following the terms and conditions either of that numbered
574 | version or of any later version published by the Free Software
575 | Foundation. If the Program does not specify a version number of the
576 | GNU General Public License, you may choose any version ever published
577 | by the Free Software Foundation.
578 |
579 | If the Program specifies that a proxy can decide which future
580 | versions of the GNU General Public License can be used, that proxy's
581 | public statement of acceptance of a version permanently authorizes you
582 | to choose that version for the Program.
583 |
584 | Later license versions may give you additional or different
585 | permissions. However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 |
589 | 15. Disclaimer of Warranty.
590 |
591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 |
600 | 16. Limitation of Liability.
601 |
602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 |
612 | 17. Interpretation of Sections 15 and 16.
613 |
614 | If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 |
621 | END OF TERMS AND CONDITIONS
622 |
623 | How to Apply These Terms to Your New Programs
624 |
625 | If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 |
629 | To do so, attach the following notices to the program. It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 |
634 |
635 | Copyright (C)
636 |
637 | This program is free software: you can redistribute it and/or modify
638 | it under the terms of the GNU General Public License as published by
639 | the Free Software Foundation, either version 3 of the License, or
640 | (at your option) any later version.
641 |
642 | This program is distributed in the hope that it will be useful,
643 | but WITHOUT ANY WARRANTY; without even the implied warranty of
644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
645 | GNU General Public License for more details.
646 |
647 | You should have received a copy of the GNU General Public License
648 | along with this program. If not, see .
649 |
650 | Also add information on how to contact you by electronic and paper mail.
651 |
652 | If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 |
655 | Copyright (C)
656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 | This is free software, and you are welcome to redistribute it
658 | under certain conditions; type `show c' for details.
659 |
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License. Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 |
664 | You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | .
668 |
669 | The GNU General Public License does not permit incorporating your program
670 | into proprietary programs. If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library. If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License. But first, please read
674 | .
675 |
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