Preprocess the dataframe X to remove newlines

khiops/sklearn/dataset.py

@@ -404,6 +404,10 @@ def write_internal_data_table(dataframe, file_path_or_stream):
     - UTF-8 encoding
     - The index is not written
 
+    Khiops cannot handle multi-line records.
+    Hence, the carriage returns / line feeds need to be removed from the records
+    before data is handed over to Khiops.
+
     Parameters
     ----------
     dataframe : `pandas.DataFrame`
@@ -412,6 +416,10 @@ def write_internal_data_table(dataframe, file_path_or_stream):
         The path of the internal data table file to be written or a writable file
         object.
     """
+    # Replace carriage returns / line feeds by blanks spaces
+    # in order to always keep mono-lines text fields
+    dataframe = dataframe.replace(["\r", "\n"], " ", regex=True)
+
     dataframe.to_csv(
         file_path_or_stream,
         sep="\t",

khiops/sklearn/estimators.py

@@ -223,6 +223,13 @@ def _cleanup_dir(target_dir):
 class KhiopsEstimator(ABC, BaseEstimator):
     """Base class for Khiops Scikit-learn estimators
 
+    .. note::
+         The input features collection X needs to have single-line records
+         so that Khiops can handle them.
+         Hence, multi-line records are preprocessed:
+         carriage returns / line feeds are replaced
+         with blank spaces before being handed over to Khiops.
+
     Parameters
     ----------
     verbose : bool, default ``False``
@@ -1695,7 +1702,7 @@ class KhiopsClassifier(ClassifierMixin, KhiopsPredictor):
     .. note::
 
         Visit `the Khiops site <https://khiops.org/learn/understand>`_ to learn
-        abouth the automatic feature engineering algorithm.
+        about the automatic feature engineering algorithm.
 
     Parameters
     ----------

tests/test_dataset_class.py

@@ -4,7 +4,6 @@
 # which is available at https://spdx.org/licenses/BSD-3-Clause-Clear.html or         #
 # see the "LICENSE.md" file for more details.                                        #
 ######################################################################################
-"""Test consistency of the created files with the input data"""
 import os
 import shutil
 import unittest
@@ -700,3 +699,47 @@ def _test_domain_coherence(self, ds, ref_var_types):
                     for var in out_domain.get_dictionary(table.name).variables
                 }
                 self.assertEqual(ref_var_types[table.name], out_dictionary_var_types)
+
+
+class DataFramePreprocessingTests(unittest.TestCase):
+    """Check that the preprocessing of X (input features collection) is actually done
+    when writing the csv used later by Khiops
+    """
+
+    def setUp(self):
+        """Set-up test-specific output directory"""
+        self.output_dir = os.path.join("resources", "tmp", self._testMethodName)
+        os.makedirs(self.output_dir, exist_ok=True)
+
+    def tearDown(self):
+        """Clean-up test-specific output directory"""
+        shutil.rmtree(self.output_dir, ignore_errors=True)
+        del self.output_dir
+
+    @staticmethod
+    def create_monotable_dataset_with_newlines():
+        data = {
+            "User_ID": [
+                "Cm6fu01r99",
+            ],
+            "Age": [39],
+            "Title": [
+                "Shimmer,\nsurprisingly\n\rgoes with lots",
+            ],
+        }
+        dataset = pd.DataFrame(data)
+        return dataset
+
+    def test_newlines_removed_from_csv_file_for_khiops(self):
+        dataset = Dataset(
+            DataFramePreprocessingTests.create_monotable_dataset_with_newlines()
+        )
+
+        out_table_path, _ = dataset.create_table_files_for_khiops(self.output_dir)
+        out_table = pd.read_csv(out_table_path, sep="\t")
+
+        self.assertEqual(
+            "Shimmer, surprisingly  goes with lots",
+            out_table.Title[0],
+            "Newlines should have been removed from the data",
+        )