Fix PropertyGraph.renumber_*_by_type with only default types

python/cugraph/cugraph/dask/structure/mg_property_graph.py

@@ -1431,7 +1431,10 @@ def renumber_vertices_by_type(self, prev_id_column=None):
         # Include self.vertex_col_name when sorting by values to ensure we can
         # evenly distribute the data across workers.
         df = df.reset_index().persist()
-        df = df.sort_values(by=[TCN, self.vertex_col_name], ignore_index=True).persist()
+        if len(self.vertex_types) > 1:
+            df = df.sort_values(
+                by=[TCN, self.vertex_col_name], ignore_index=True
+            ).persist()
         if self.__edge_prop_dataframe is not None:
             new_name = f"new_{self.vertex_col_name}"
             df[new_name] = 1
@@ -1522,9 +1525,10 @@ def renumber_edges_by_type(self, prev_id_column=None):
         # Include self.edge_id_col_name when sorting by values to ensure we can
         # evenly distribute the data across workers.
         df = df.reset_index().persist()
-        df = df.sort_values(
-            by=[self.type_col_name, self.edge_id_col_name], ignore_index=True
-        ).persist()
+        if len(self.edge_types) > 1:
+            df = df.sort_values(
+                by=[self.type_col_name, self.edge_id_col_name], ignore_index=True
+            ).persist()
         if prev_id_column is not None:
             df[prev_id_column] = df[self.edge_id_col_name]
 
@@ -1540,8 +1544,8 @@ def renumber_edges_by_type(self, prev_id_column=None):
 
         # FIXME DASK_CUDF: https://github.com/rapidsai/cudf/issues/11795
         df = self._edge_type_value_counts
-        assert df.index.dtype == cat_dtype
-        df.index = df.index.astype(str)
+        if df.index.dtype == cat_dtype:
+            df.index = df.index.astype(str)
 
         # self._edge_type_value_counts
         rv = df.sort_index().cumsum().to_frame("stop")

python/cugraph/cugraph/structure/property_graph.py

@@ -1982,6 +1982,7 @@ def renumber_vertices_by_type(self, prev_id_column=None):
             ].astype(cat_dtype)
 
         index_dtype = self.__vertex_prop_dataframe.index.dtype
+        # Should we avoid `sort_values` if we know there is only one type?
         df = self.__vertex_prop_dataframe.reset_index().sort_values(by=TCN)
         df.index = df.index.astype(index_dtype)
         if self.__edge_prop_dataframe is not None:
@@ -2071,6 +2072,7 @@ def renumber_edges_by_type(self, prev_id_column=None):
 
         df = self.__edge_prop_dataframe
         index_dtype = df.index.dtype
+        # Should we avoid `sort_values` if we know there is only one type?
         if prev_id_column is None:
             df = df.sort_values(by=TCN, ignore_index=True)
         else:

python/cugraph/cugraph/tests/data_store/test_property_graph_mg.py

@@ -1476,6 +1476,37 @@ def test_types_from_numerals(dask_client):
     ]
 
 
+@pytest.mark.mg
+def test_renumber_by_type_only_default_type(dask_client):
+    from cugraph.experimental import MGPropertyGraph
+
+    pG = MGPropertyGraph()
+    df = cudf.DataFrame(
+        {
+            "src": cp.array([0, 0, 1, 2, 2, 3], dtype="int32"),
+            "dst": cp.array([1, 2, 4, 3, 4, 1], dtype="int32"),
+        }
+    )
+    ddf = dask_cudf.from_cudf(df, npartitions=2)
+    pG.add_edge_data(ddf, vertex_col_names=["src", "dst"])
+
+    df2 = cudf.DataFrame(
+        {
+            "prop1": [100, 200, 300, 400, 500],
+            "prop2": [5, 4, 3, 2, 1],
+            "id": cp.array([0, 1, 2, 3, 4], dtype="int32"),
+        }
+    )
+    ddf2 = dask_cudf.from_cudf(df2, npartitions=2)
+    pG.add_vertex_data(ddf2, vertex_col_name="id")
+    pG.renumber_vertices_by_type()
+    got = pG.get_vertex_data().compute()
+    assert got[pG.vertex_col_name].to_arrow().to_pylist() == list(range(len(got)))
+    pG.renumber_edges_by_type()
+    got = pG.get_edge_data().compute()
+    assert got[pG.edge_id_col_name].to_arrow().to_pylist() == list(range(len(got)))
+
+
 # =============================================================================
 # Benchmarks
 # =============================================================================