diff --git a/swh/core/tests/test_utils.py b/swh/core/tests/test_utils.py
new file mode 100644
index 0000000..a2fe4a1
--- /dev/null
+++ b/swh/core/tests/test_utils.py
@@ -0,0 +1,33 @@
+# Copyright (C) 2015-2016  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+import unittest
+
+from nose.tools import istest
+
+from swh.core import utils
+
+
+class UtilsLib(unittest.TestCase):
+
+    @istest
+    def grouper(self):
+        # given
+        actual_data = utils.grouper((i for i in range(0, 9)), 2)
+
+        out = []
+        for d in actual_data:
+            out.append(list(d))  # force generator resolution for checks
+
+        self.assertEqual(out, [[0, 1], [2, 3], [4, 5], [6, 7], [8]])
+
+        # given
+        actual_data = utils.grouper((i for i in range(9, 0, -1)), 4)
+
+        out = []
+        for d in actual_data:
+            out.append(list(d))  # force generator resolution for checks
+
+        self.assertEqual(out, [[9, 8, 7, 6], [5, 4, 3, 2], [1]])
diff --git a/swh/core/utils.py b/swh/core/utils.py
new file mode 100644
index 0000000..4a225ef
--- /dev/null
+++ b/swh/core/utils.py
@@ -0,0 +1,24 @@
+# Copyright (C) 2016  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+
+import itertools
+
+
+def grouper(iterable, n):
+    """Collect data into fixed-length chunks or blocks.
+
+    Args:
+        iterable: an iterable
+        n: size of block
+        fillvalue: value to use for the last block
+
+    Returns:
+        fixed-length chunks of blocks as iterables
+
+    """
+    args = [iter(iterable)] * n
+    for _data in itertools.zip_longest(*args, fillvalue=None):
+        yield (d for d in _data if d is not None)