dataset: add session-aware datasets: Diginetica, RetailRocket, and Cosmetics

cornac/datasets/README.md

@@ -268,3 +268,14 @@ Our dataset is now ready to use for model training and evaluation. A concrete ex
     <td align="center">N/A</td>
   </tr>
 </table>
+
+---
+
+## Session-aware Datasets
+Session-aware recommendation extends next-item (session-based) recommendation by associating sessions with identified users. While next-item datasets rely on session-level sequences (e.g., `SIT` format), session-aware datasets incorporate user identities (e.g., `USIT` format), allowing models to capture both long-term user preferences across multiple sessions and short-term session-level dynamics.
+
+| Dataset                           | #Users | #Items | #Sessions | #Interactions | #Sessions per User | #Interactions per Item | #Interactions per Session | Density |
+| :-------------------------------- | -----: | -----: | --------: | ------------: | -----------------: | ---------------------: | ------------------------: | ------: |
+| [Diginetica](./diginetica.py)     |    571 |  6,008 |     2,670 |        12,146 |               4.68 |                   2.02 |                      4.55 |  0.354% |
+| [RetailRocket](./retailrocket.py) |  4,249 | 36,658 |    24,732 |       230,817 |               5.82 |                   6.30 |                      9.33 |  0.148% |
+| [Cosmetics](./cosmetics.py)       | 17,268 | 42,367 |   172,242 |     2,533,262 |               9.97 |                  59.79 |                     14.71 |  0.346% |

cornac/datasets/__init__.py

@@ -18,11 +18,14 @@
 from . import amazon_office
 from . import amazon_toy
 from . import citeulike
+from . import cosmetics
+from . import diginetica
 from . import epinions
 from . import filmtrust
 from . import gowalla
 from . import movielens
 from . import netflix
+from . import retailrocket
 from . import tafeng
 from . import tradesy
 from . import yoochoose

cornac/datasets/cosmetics.py

@@ -0,0 +1,88 @@
+# Copyright 2026 The Cornac Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+"""
+Cosmetics dataset: an e-commerce dataset containing the event history of a cosmetics shop for five months.
+"""
+
+from typing import List
+
+from ..data import Reader
+from ..utils import cache
+
+
+def load_train(fmt="USIT", reader: Reader = None) -> List:
+    """Load train data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/cosmetics/train.zip",
+        unzip=True,
+        relative_path="cosmetics/train.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_val(fmt="USIT", reader: Reader = None) -> List:
+    """Load validation data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/cosmetics/val.zip",
+        unzip=True,
+        relative_path="cosmetics/val.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_test(fmt="USIT", reader: Reader = None) -> List:
+    """Load test data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/cosmetics/test.zip",
+        unzip=True,
+        relative_path="cosmetics/test.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")

cornac/datasets/diginetica.py

@@ -0,0 +1,88 @@
+# Copyright 2026 The Cornac Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+"""
+Diginetica dataset is originally from the CIKM 2016 competition.
+"""
+
+from typing import List
+
+from ..data import Reader
+from ..utils import cache
+
+
+def load_train(fmt="USIT", reader: Reader = None) -> List:
+    """Load train data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/diginetica/train.zip",
+        unzip=True,
+        relative_path="diginetica/train.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_val(fmt="USIT", reader: Reader = None) -> List:
+    """Load validation data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/diginetica/val.zip",
+        unzip=True,
+        relative_path="diginetica/val.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_test(fmt="USIT", reader: Reader = None) -> List:
+    """Load test data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/diginetica/test.zip",
+        unzip=True,
+        relative_path="diginetica/test.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")

cornac/datasets/retailrocket.py

@@ -0,0 +1,88 @@
+# Copyright 2026 The Cornac Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+"""
+RetailRocket dataset: e-commerce web events (clicks, add to carts, transactions) data for 4.5 months.
+"""
+
+from typing import List
+
+from ..data import Reader
+from ..utils import cache
+
+
+def load_train(fmt="USIT", reader: Reader = None) -> List:
+    """Load train data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/retailrocket/train.zip",
+        unzip=True,
+        relative_path="retailrocket/train.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_val(fmt="USIT", reader: Reader = None) -> List:
+    """Load validation data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/retailrocket/val.zip",
+        unzip=True,
+        relative_path="retailrocket/val.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")
+
+
+def load_test(fmt="USIT", reader: Reader = None) -> List:
+    """Load test data
+
+    Parameters
+    ----------
+    reader: `obj:cornac.data.Reader`, default: None
+        Reader object used to read the data.
+
+    Returns
+    -------
+    data: array-like
+        Data in the form of a list of tuples (user, session, item, timestamp).
+    """
+    fpath = cache(
+        url="https://static.preferred.ai/cornac/datasets/retailrocket/test.zip",
+        unzip=True,
+        relative_path="retailrocket/test.csv",
+    )
+    reader = Reader() if reader is None else reader
+    return reader.read(fpath, fmt=fmt, sep=",")

tests/cornac/datasets/test_cosmetics.py

@@ -0,0 +1,38 @@
+# Copyright 2026 The Cornac Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+import random
+import time
+import unittest
+
+from cornac.datasets import cosmetics
+
+
+class TestCosmetics(unittest.TestCase):
+
+    def test_load_train_val_test(self):
+        random.seed(time.time())
+        if random.random() > 0.8:
+            train = cosmetics.load_train()
+            val = cosmetics.load_val()
+            test = cosmetics.load_test()
+
+            self.assertEqual(len(train), 2069928)
+            self.assertEqual(len(val), 2302227)
+            self.assertEqual(len(test), 2300963)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/cornac/datasets/test_diginetica.py

@@ -0,0 +1,38 @@
+# Copyright 2026 The Cornac Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+import random
+import time
+import unittest
+
+from cornac.datasets import diginetica
+
+
+class TestDiginetica(unittest.TestCase):
+
+    def test_load_train_val_test(self):
+        random.seed(time.time())
+        if random.random() > 0.8:
+            train = diginetica.load_train()
+            val = diginetica.load_val()
+            test = diginetica.load_test()
+
+            self.assertEqual(len(train), 7273)
+            self.assertEqual(len(val), 9733)
+            self.assertEqual(len(test), 9686)
+
+
+if __name__ == "__main__":
+    unittest.main()