Add get_num_vertices and get_num_edges methods to PropertyGraph. (rap…

…idsai#2434)

Closes rapidsai#2422.  I'll add this to MGPG when we finalize the API and behavior.

Authors:
  - Erik Welch (https://github.com/eriknw)

Approvers:
  - Alex Barghi (https://github.com/alexbarghi-nv)
  - Brad Rees (https://github.com/BradReesWork)
  - Rick Ratzel (https://github.com/rlratzel)

URL: rapidsai#2434

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

@@ -52,7 +52,6 @@ class EXPERIMENTAL__MGPropertyGraph:
     Graphs from individual property selections and used later to annotate graph
     algorithm results with corresponding properties.
     """
-
     # column name constants used in internal DataFrames
     vertex_col_name = "_VERTEX_"
     src_col_name = "_SRC_"
@@ -61,6 +60,7 @@ class EXPERIMENTAL__MGPropertyGraph:
     edge_id_col_name = "_EDGE_ID_"
     vertex_id_col_name = "_VERTEX_ID_"
     weight_col_name = "_WEIGHT_"
+    _default_type_name = ""
 
     def __init__(self, num_workers=None):
         # The dataframe containing the properties for each vertex.
@@ -126,45 +126,16 @@ def __init__(self, num_workers=None):
 
         # Cached property values
         self.__num_vertices = None
-        self.__num_vertices_with_properties = None
+        self.__vertex_type_value_counts = None
+        self.__edge_type_value_counts = None
 
         # number of gpu's to use
         if num_workers is None:
             self.__num_workers = dcg.get_n_workers()
         else:
             self.__num_workers = num_workers
 
-    @property
-    def num_vertices(self):
-        if self.__num_vertices is not None:
-            return self.__num_vertices
-        self.__num_vertices = 0
-        vert_sers = self.__get_all_vertices_series()
-        if vert_sers:
-            if self.__series_type is dask_cudf.Series:
-                vert_count = dask_cudf.concat(vert_sers).nunique()
-                self.__num_vertices = vert_count.compute()
-        return self.__num_vertices
-
-    @property
-    def num_vertices_with_properties(self):
-        if self.__num_vertices_with_properties is not None:
-            return self.__num_vertices_with_properties
-
-        if self.__vertex_prop_dataframe is not None:
-            self.__num_vertices_with_properties = \
-                len(self.__vertex_prop_dataframe)
-            return self.__num_vertices_with_properties
-
-        return 0
-
-    @property
-    def num_edges(self):
-        if self.__edge_prop_dataframe is not None:
-            return len(self.__edge_prop_dataframe)
-        else:
-            return 0
-
+    # PropertyGraph read-only attributes
     @property
     def edges(self):
         if self.__edge_prop_dataframe is not None:
@@ -195,6 +166,33 @@ def edge_property_names(self):
             return props
         return []
 
+    @property
+    def vertex_types(self):
+        """The set of vertex type names"""
+        value_counts = self._vertex_type_value_counts
+        if value_counts is None:
+            names = set()
+        elif self.__series_type is dask_cudf.Series:
+            names = set(value_counts.index.to_arrow().to_pylist())
+        else:
+            names = set(value_counts.index)
+        default = self._default_type_name
+        if default not in names and self.get_num_vertices(default) > 0:
+            # include "" from vertices that only exist in edge data
+            names.add(default)
+        return names
+
+    @property
+    def edge_types(self):
+        """The set of edge type names"""
+        value_counts = self._edge_type_value_counts
+        if value_counts is None:
+            return set()
+        elif self.__series_type is dask_cudf.Series:
+            return set(value_counts.index.to_arrow().to_pylist())
+        else:
+            return set(value_counts.index)
+
     # PropertyGraph read-only attributes for debugging
     @property
     def _vertex_prop_dataframe(self):
@@ -204,6 +202,104 @@ def _vertex_prop_dataframe(self):
     def _edge_prop_dataframe(self):
         return self.__edge_prop_dataframe
 
+    @property
+    def _vertex_type_value_counts(self):
+        """A Series of the counts of types in __vertex_prop_dataframe"""
+        if self.__vertex_prop_dataframe is None:
+            return
+        if self.__vertex_type_value_counts is None:
+            # Types should all be strings; what should we do if we see NaN?
+            self.__vertex_type_value_counts = (
+                self.__vertex_prop_dataframe[self.type_col_name]
+                .value_counts(sort=False, dropna=False)
+                .compute()
+            )
+        return self.__vertex_type_value_counts
+
+    @property
+    def _edge_type_value_counts(self):
+        """A Series of the counts of types in __edge_prop_dataframe"""
+        if self.__edge_prop_dataframe is None:
+            return
+        if self.__edge_type_value_counts is None:
+            # Types should all be strings; what should we do if we see NaN?
+            self.__edge_type_value_counts = (
+                self.__edge_prop_dataframe[self.type_col_name]
+                .value_counts(sort=False, dropna=False)
+                .compute()
+            )
+        return self.__edge_type_value_counts
+
+    def get_num_vertices(self, type=None, *, include_edge_data=True):
+        """Return the number of all vertices or vertices of a given type.
+
+        Parameters
+        ----------
+        type : string, optional
+            If type is None (the default), return the total number of vertices,
+            otherwise return the number of vertices of the specified type.
+        include_edge_data : bool (default True)
+            If True, include vertices that were added in vertex and edge data.
+            If False, only include vertices that were added in vertex data.
+            Note that vertices that only exist in edge data are assumed to have
+            the default type.
+
+        See Also
+        --------
+        PropertyGraph.get_num_edges
+        """
+        if type is None:
+            if not include_edge_data:
+                if self.__vertex_prop_dataframe is None:
+                    return 0
+                return len(self.__vertex_prop_dataframe)
+            if self.__num_vertices is not None:
+                return self.__num_vertices
+            self.__num_vertices = 0
+            vert_sers = self.__get_all_vertices_series()
+            if vert_sers:
+                if self.__series_type is dask_cudf.Series:
+                    vert_count = dask_cudf.concat(vert_sers).nunique()
+                    self.__num_vertices = vert_count.compute()
+            return self.__num_vertices
+
+        value_counts = self._vertex_type_value_counts
+        if type == self._default_type_name and include_edge_data:
+            # The default type, "", can refer to both vertex and edge data
+            if self.__vertex_prop_dataframe is None:
+                return self.get_num_vertices()
+            return (
+                self.get_num_vertices()
+                - len(self.__vertex_prop_dataframe)
+                + (value_counts[type] if type in value_counts else 0)
+            )
+        if self.__vertex_prop_dataframe is None:
+            return 0
+        return value_counts[type] if type in value_counts else 0
+
+    def get_num_edges(self, type=None):
+        """Return the number of all edges or edges of a given type.
+
+        Parameters
+        ----------
+        type : string, optional
+            If type is None (the default), return the total number of edges,
+            otherwise return the number of edges of the specified type.
+
+        See Also
+        --------
+        PropertyGraph.get_num_vertices
+        """
+        if type is None:
+            if self.__edge_prop_dataframe is not None:
+                return len(self.__edge_prop_dataframe)
+            else:
+                return 0
+        if self.__edge_prop_dataframe is None:
+            return 0
+        value_counts = self._edge_type_value_counts
+        return value_counts[type] if type in value_counts else 0
+
     def get_vertices(self, selection=None):
         """
         Return a Series containing the unique vertex IDs contained in both
@@ -243,7 +339,7 @@ def add_vertex_data(self,
             The name to be assigned to the type of property being added. For
             example, if dataframe contains data about users, type_name might be
             "users". If not specified, the type of properties will be added as
-            None or NA
+            the empty string, "".
         property_columns : list of strings
             List of column names in dataframe to be added as properties. All
             other columns in dataframe will be ignored. If not specified, all
@@ -265,6 +361,8 @@ def add_vertex_data(self,
         if (type_name is not None) and not(isinstance(type_name, str)):
             raise TypeError("type_name must be a string, got: "
                             f"{type(type_name)}")
+        if type_name is None:
+            type_name = self._default_type_name
         if property_columns:
             if type(property_columns) is not list:
                 raise TypeError("property_columns must be a list, got: "
@@ -279,7 +377,7 @@ def add_vertex_data(self,
         # Clear the cached values related to the number of vertices since more
         # could be added in this method.
         self.__num_vertices = None
-        self.__num_vertices_with_properties = None
+        self.__vertex_type_value_counts = None  # Could update instead
 
         # Initialize the __vertex_prop_dataframe if necessary using the same
         # type as the incoming dataframe.
@@ -352,7 +450,7 @@ def add_edge_data(self,
             The name to be assigned to the type of property being added. For
             example, if dataframe contains data about transactions, type_name
             might be "transactions". If not specified, the type of properties
-            will be added as None or NA
+            will be added as the empty string "".
         property_columns : list of strings
             List of column names in dataframe to be added as properties. All
             other columns in dataframe will be ignored. If not specified, all
@@ -378,6 +476,8 @@ def add_edge_data(self,
         if (type_name is not None) and not(isinstance(type_name, str)):
             raise TypeError("type_name must be a string, got: "
                             f"{type(type_name)}")
+        if type_name is None:
+            type_name = self._default_type_name
         if property_columns:
             if type(property_columns) is not list:
                 raise TypeError("property_columns must be a list, got: "
@@ -390,8 +490,9 @@ def add_edge_data(self,
                                  f"{list(invalid_columns)}")
 
         # Clear the cached value for num_vertices since more could be added in
-        # this method. This method cannot affect num_vertices_with_properties
+        # this method. This method cannot affect __node_type_value_counts
         self.__num_vertices = None
+        self.__edge_type_value_counts = None  # Could update instead
 
         default_edge_columns = [self.src_col_name,
                                 self.dst_col_name,
@@ -521,6 +622,7 @@ def extract_subgraph(self,
         add_edge_data : bool (default is True)
             If True, add meta data about the edges contained in the extracted
             graph which are required for future calls to annotate_dataframe().
+
         Returns
         -------
         A Graph instance of the same type as create_using containing only the

python/cugraph/cugraph/gnn/graph_store.py

@@ -117,18 +117,10 @@ def get_edge_storage(self, key, etype=None):
         )
 
     def num_nodes(self, ntype=None):
-        if ntype is not None:
-            s = self.gdata._vertex_prop_dataframe[type_n] == ntype
-            return s.sum()
-        else:
-            return self.gdata.num_vertices
+        return self.gdata.get_num_vertices(ntype)
 
     def num_edges(self, etype=None):
-        if etype is not None:
-            s = self.gdata._edge_prop_dataframe[type_n] == etype
-            return s.sum()
-        else:
-            return self.gdata.num_edges
+        return self.gdata.get_num_edges(etype)
 
     @property
     def ntypes(self):
@@ -165,7 +157,7 @@ def gdata(self):
     ######################################
     @property
     def num_vertices(self):
-        return self.gdata.num_vertices
+        return self.gdata.get_num_vertices()
 
     def get_vertex_ids(self):
         return self.gdata.vertices_ids()