Test added: uint64 multicolumn sort (pandas-dev#29365)

Author: pv8473h12

pandas/tests/frame/test_sorting.py

@@ -735,3 +735,26 @@ def test_sort_index_na_position_with_categories_raises(self):
 
         with pytest.raises(ValueError):
             df.sort_values(by="c", ascending=False, na_position="bad_position")
+
+    def test_sort_multicolumn_uint64(self):
+        # GH9918
+        # uint64 multicolumn sort
+
+        df = pd.DataFrame(
+            {
+                "a": pd.Series([18446637057563306014, 1162265347240853609]),
+                "b": pd.Series([1, 2]),
+            }
+        )
+        df["a"] = df["a"].astype(np.uint64)
+        result = df.sort_values(["a", "b"])
+
+        expected = pd.DataFrame(
+            {
+                "a": pd.Series([18446637057563306014, 1162265347240853609]),
+                "b": pd.Series([1, 2]),
+            },
+            index=pd.Index([1, 0]),
+        )
+
+        tm.assert_frame_equal(result, expected)