Update test_splitting.py

Adjusted the test cases to the new OO-implementation of splitting.py

data_processing/test_splitting.py

@@ -14,26 +14,31 @@ def setUp(self):
             'label': np.random.choice([0, 1], size=num_samples)
         }
         self.df = pd.DataFrame(data)
+        self.splitter = None
 
     def test_split_k_folds(self):
-        df_result = split_K_stratified_folds(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        self.splitter = Splitting(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        df_result = self.splitter.split_K_stratified_folds()
         unique_folds = df_result['fold'].unique()
 
         self.assertEqual(len(unique_folds), 5)  # Check if correct number of folds are created
 
     def test_split_k_folds_verbose(self):
-        df_result = split_K_stratified_folds(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'], verbose=True)
+        self.splitter = Splitting(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'], verbose=True)
+        df_result =self.splitter.split_K_stratified_folds()
 
         unique_folds = df_result['fold'].unique()
 
         self.assertEqual(len(unique_folds), 5)  # Check if correct number of folds are created
 
     def test_split_k_folds_labels(self):
-        df_result = split_K_stratified_folds(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        self.splitter = Splitting(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        df_result =self.splitter.split_K_stratified_folds()
         unique_labels = df_result.set_index(['fold', 'label']).groupby(level='label').count()
 
         self.assertTrue(unique_labels.min()['id'] > 1)  # Check if each label has samples in each fold
 
     def test_split_k_folds_reset_index(self):
-        df_result = split_K_stratified_folds(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        self.splitter = Splitting(self.df, nfolds=5, seed=42, id_key='id', split_key='split_key', label_keys=['label'])
+        df_result =self.splitter.split_K_stratified_folds()
         self.assertTrue('id' in df_result.columns)  # Check if 'id' column is present after resetting index