Fix unleved bug with bert (#138)

Author: mirand863

hiclass/HierarchicalClassifier.py

@@ -161,7 +161,9 @@ def _pre_fit(self, X, y, sample_weight):
             )
         else:
             self.X_ = np.array(X)
-            self.y_ = np.array(y)
+            self.y_ = check_array(
+                make_leveled(y), dtype=None, ensure_2d=False, allow_nd=True
+            )
 
         if sample_weight is not None:
             self.sample_weight_ = _check_sample_weight(sample_weight, X)

setup.py

@@ -45,6 +45,7 @@
         "ray",
         "shap==0.44.1",
         "xarray==2023.1.0",
+        "bert-sklearn @ git+https://github.com/charles9n/bert-sklearn.git#egg=bert-sklearn",
     ],
 }
 

tests/test_LocalClassifierPerParentNode.py

@@ -4,12 +4,14 @@
 import networkx as nx
 import numpy as np
 import pytest
-from numpy.testing import assert_array_equal, assert_array_almost_equal
+from bert_sklearn import BertClassifier
+from numpy.testing import assert_array_almost_equal, assert_array_equal
 from scipy.sparse import csr_matrix
 from sklearn.exceptions import NotFittedError
 from sklearn.linear_model import LogisticRegression
 from sklearn.utils.estimator_checks import parametrize_with_checks
 from sklearn.utils.validation import check_is_fitted
+
 from hiclass import LocalClassifierPerParentNode
 from hiclass._calibration.Calibrator import _Calibrator
 from hiclass.HierarchicalClassifier import make_leveled
@@ -393,3 +395,37 @@ def test_fit_calibrate_predict_predict_proba_bert():
     classifier.calibrate(x, y)
     classifier.predict(x)
     classifier.predict_proba(x)
+
+
+# Note: bert only works with the local classifier per parent node
+# It does not have the attribute classes_, which are necessary
+# for the local classifiers per level and per node
+def test_fit_bert():
+    bert = BertClassifier()
+    clf = LocalClassifierPerParentNode(
+        local_classifier=bert,
+        bert=True,
+    )
+    x = ["Batman", "rorschach"]
+    y = [
+        ["Action", "The Dark Night"],
+        ["Action", "Watchmen"],
+    ]
+    clf.fit(x, y)
+    check_is_fitted(clf)
+    predictions = clf.predict(x)
+    assert_array_equal(y, predictions)
+
+
+def test_bert_unleveled():
+    clf = LocalClassifierPerParentNode(
+        local_classifier=BertClassifier(),
+        bert=True,
+    )
+    x = ["Batman", "Jaws"]
+    y = [["Action", "The Dark Night"], ["Thriller"]]
+    ground_truth = [["Action", "The Dark Night"], ["Action", "The Dark Night"]]
+    clf.fit(x, y)
+    check_is_fitted(clf)
+    predictions = clf.predict(x)
+    assert_array_equal(ground_truth, predictions)

tests/test_LocalClassifiers.py

@@ -10,8 +10,8 @@
 from sklearn.utils.validation import check_is_fitted
 
 from hiclass import (
-    LocalClassifierPerNode,
     LocalClassifierPerLevel,
+    LocalClassifierPerNode,
     LocalClassifierPerParentNode,
 )
 from hiclass.ConstantClassifier import ConstantClassifier
@@ -75,21 +75,6 @@ def test_empty_levels(empty_levels, classifier):
     assert_array_equal(ground_truth, predictions)
 
 
-@pytest.mark.parametrize("classifier", classifiers)
-def test_fit_bert(classifier):
-    bert = ConstantClassifier()
-    clf = classifier(
-        local_classifier=bert,
-        bert=True,
-    )
-    X = ["Text 1", "Text 2"]
-    y = ["a", "a"]
-    clf.fit(X, y)
-    check_is_fitted(clf)
-    predictions = clf.predict(X)
-    assert_array_equal(y, predictions)
-
-
 @pytest.mark.parametrize("classifier", classifiers)
 def test_knn(classifier):
     knn = KNeighborsClassifier(