add multi-label support

xgboost_ray/data_sources/data_source.py

@@ -1,5 +1,5 @@
 from enum import Enum
-from typing import TYPE_CHECKING, Any, Dict, List, Optional, Sequence, Tuple
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, Sequence, Tuple, Union
 
 import pandas as pd
 from ray.actor import ActorHandle
@@ -118,12 +118,12 @@ def convert_to_series(data: Any) -> pd.Series:
     @classmethod
     def get_column(
         cls, data: pd.DataFrame, column: Any
-    ) -> Tuple[pd.Series, Optional[str]]:
+    ) -> Tuple[pd.Series, Optional[Union[str, List]]]:
         """Helper method wrapping around convert to series.
 
         This method should usually not be overwritten.
         """
-        if isinstance(column, str):
+        if isinstance(column, str) or isinstance(column, List):
             return data[column], column
         elif column is not None:
             return cls.convert_to_series(column), None

xgboost_ray/matrix.py

@@ -31,7 +31,6 @@
 from ray.util.annotations import DeveloperAPI, PublicAPI
 
 from xgboost_ray.data_sources import DataSource, RayFileType, data_sources
-
 try:
     from ray.data.dataset import Dataset as RayDataset
 except ImportError:
@@ -307,7 +306,10 @@ def _split_dataframe(
 
         label, exclude = data_source.get_column(local_data, self.label)
         if exclude:
-            exclude_cols.add(exclude)
+            if isinstance(exclude, List):
+                exclude_cols.update(exclude)
+            else:
+                exclude_cols.add(exclude)
 
         weight, exclude = data_source.get_column(local_data, self.weight)
         if exclude:
@@ -406,7 +408,10 @@ def get_data_source(self) -> Type[DataSource]:
         ):  # noqa: E721:
             # Label is an object of a different type than the main data.
             # We have to make sure they are compatible
-            if not data_source.is_data_type(self.label):
+            # if it's a parquet data source and label is a list, then we consider it a multi-label data
+            if not data_source.is_data_type(self.label) \
+                and not (isinstance(self.label, List) \
+                and data_source.__name__ == "Parquet"):
                 raise ValueError(
                     "The passed `data` and `label` types are not compatible."
                     "\nFIX THIS by passing the same types to the "
@@ -521,7 +526,7 @@ def get_data_source(self) -> Type[DataSource]:
                 f"RayDMatrix."
             )
 
-        if self.label is not None and not isinstance(self.label, str):
+        if self.label is not None and not isinstance(self.label, str) and not isinstance(self.label, List):
             raise ValueError(
                 f"Invalid `label` value for distributed datasets: "
                 f"{self.label}. Only strings are supported. "

xgboost_ray/tests/test_matrix.py

@@ -33,6 +33,15 @@ def setUp(self):
             * repeat
         )
         self.y = np.array([0, 1, 2, 3] * repeat)
+        self.multi_y = np.array(
+            [
+                [1, 0, 0, 0],
+                [0, 1, 0, 0],
+                [0, 0, 1, 1],
+                [0, 0, 1, 0],
+            ]
+            * repeat
+        )
 
     @classmethod
     def setUpClass(cls):
@@ -62,7 +71,7 @@ def testColumnOrdering(self):
 
         assert data.columns.tolist() == cols[:-1]
 
-    def _testMatrixCreation(self, in_x, in_y, **kwargs):
+    def _testMatrixCreation(self, in_x, in_y, multi_label = False, **kwargs):
         if "sharding" not in kwargs:
             kwargs["sharding"] = RayShardingMode.BATCH
         mat = RayDMatrix(in_x, in_y, **kwargs)
@@ -81,7 +90,10 @@ def _load_data(params):
         x, y = _load_data(params)
 
         self.assertTrue(np.allclose(self.x, x))
-        self.assertTrue(np.allclose(self.y, y))
+        if multi_label:
+            self.assertTrue(np.allclose(self.multi_y, y))
+        else:
+            self.assertTrue(np.allclose(self.y, y))
 
         # Multi actor check
         mat = RayDMatrix(in_x, in_y, **kwargs)
@@ -95,7 +107,10 @@ def _load_data(params):
         x2, y2 = _load_data(params)
 
         self.assertTrue(np.allclose(self.x, concat_dataframes([x1, x2])))
-        self.assertTrue(np.allclose(self.y, concat_dataframes([y1, y2])))
+        if multi_label:
+            self.assertTrue(np.allclose(self.multi_y, concat_dataframes([y1, y2])))
+        else:
+            self.assertTrue(np.allclose(self.y, concat_dataframes([y1, y2])))
 
     def testFromNumpy(self):
         in_x = self.x
@@ -276,6 +291,18 @@ def testFromMultiCSVString(self):
                 [data_file_1, data_file_2], "label", distributed=True
             )
 
+    def testFromParquetStringMultiLabel(self):
+        with tempfile.TemporaryDirectory() as dir:
+            data_file = os.path.join(dir, "data.parquet")
+
+            data_df = pd.DataFrame(self.x, columns=["a", "b", "c", "d"])
+            labels = [f"label_{label}" for label in range(4)]
+            data_df[labels] = self.multi_y
+            data_df.to_parquet(data_file)
+
+            self._testMatrixCreation(data_file, labels, multi_label=True, distributed=False)
+            self._testMatrixCreation(data_file, labels, multi_label=True, distributed=True)
+
     def testFromParquetString(self):
         with tempfile.TemporaryDirectory() as dir:
             data_file = os.path.join(dir, "data.parquet")
@@ -286,6 +313,28 @@ def testFromParquetString(self):
 
             self._testMatrixCreation(data_file, "label", distributed=False)
             self._testMatrixCreation(data_file, "label", distributed=True)
+
+    def testFromMultiParquetStringMultiLabel(self):
+        with tempfile.TemporaryDirectory() as dir:
+            data_file_1 = os.path.join(dir, "data_1.parquet")
+            data_file_2 = os.path.join(dir, "data_2.parquet")
+
+            data_df = pd.DataFrame(self.x, columns=["a", "b", "c", "d"])
+            labels = [f"label_{label}" for label in range(4)]
+            data_df[labels] = self.multi_y
+
+            df_1 = data_df[0 : len(data_df) // 2]
+            df_2 = data_df[len(data_df) // 2 :]
+
+            df_1.to_parquet(data_file_1)
+            df_2.to_parquet(data_file_2)
+
+            self._testMatrixCreation(
+                [data_file_1, data_file_2], labels, multi_label=True, distributed=False
+            )
+            self._testMatrixCreation(
+                [data_file_1, data_file_2], labels, multi_label=True, distributed=True
+            )
 
     def testFromMultiParquetString(self):
         with tempfile.TemporaryDirectory() as dir: