feat: graph attributes now accessible from Python

Author: ntamas

src/codegen/internal_lib.py.in

@@ -1,6 +1,6 @@
 # fmt: off
 
-from ctypes import cdll, c_char_p, c_double, c_int, c_void_p, POINTER
+from ctypes import cdll, c_char_p, c_double, c_int, c_size_t, c_void_p, POINTER
 from ctypes.util import find_library
 from typing import Any
 
@@ -79,18 +79,30 @@ igraph_vector_view = _lib.igraph_vector_view
 igraph_vector_view.restype = POINTER(igraph_vector_t)
 igraph_vector_view.argtypes = [POINTER(igraph_vector_t), POINTER(igraph_real_t), igraph_integer_t]
 
-igraph_vector_e = _lib.igraph_vector_e
-igraph_vector_e.restype = igraph_real_t
-igraph_vector_e.argtypes = [POINTER(igraph_vector_t), igraph_integer_t]
+igraph_vector_clear = _lib.igraph_vector_clear
+igraph_vector_clear.restype = None
+igraph_vector_clear.argtypes = [POINTER(igraph_vector_t)]
 
-igraph_vector_e_ptr = _lib.igraph_vector_e_ptr
-igraph_vector_e_ptr.restype = POINTER(igraph_real_t)
-igraph_vector_e_ptr.argtypes = [POINTER(igraph_vector_t), igraph_integer_t]
+igraph_vector_get = _lib.igraph_vector_get
+igraph_vector_get.restype = igraph_real_t
+igraph_vector_get.argtypes = [POINTER(igraph_vector_t), igraph_integer_t]
+
+igraph_vector_get_ptr = _lib.igraph_vector_get_ptr
+igraph_vector_get_ptr.restype = POINTER(igraph_real_t)
+igraph_vector_get_ptr.argtypes = [POINTER(igraph_vector_t), igraph_integer_t]
 
 igraph_vector_push_back = _lib.igraph_vector_push_back
 igraph_vector_push_back.restype = handle_igraph_error_t
 igraph_vector_push_back.argtypes = [POINTER(igraph_vector_t), igraph_real_t]
 
+igraph_vector_resize = _lib.igraph_vector_resize
+igraph_vector_resize.restype = handle_igraph_error_t
+igraph_vector_resize.argtypes = [POINTER(igraph_vector_t), igraph_integer_t]
+
+igraph_vector_set = _lib.igraph_vector_set
+igraph_vector_set.restype = None
+igraph_vector_set.argtypes = [POINTER(igraph_vector_t), igraph_integer_t, igraph_real_t]
+
 igraph_vector_size = _lib.igraph_vector_size
 igraph_vector_size.restype = igraph_integer_t
 igraph_vector_size.argtypes = [POINTER(igraph_vector_t)]
@@ -113,18 +125,30 @@ igraph_vector_int_view = _lib.igraph_vector_int_view
 igraph_vector_int_view.restype = POINTER(igraph_vector_int_t)
 igraph_vector_int_view.argtypes = [POINTER(igraph_vector_int_t), POINTER(igraph_integer_t), igraph_integer_t]
 
-igraph_vector_int_e = _lib.igraph_vector_int_e
-igraph_vector_int_e.restype = igraph_integer_t
-igraph_vector_int_e.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
+igraph_vector_int_clear = _lib.igraph_vector_int_clear
+igraph_vector_int_clear.restype = None
+igraph_vector_int_clear.argtypes = [POINTER(igraph_vector_int_t)]
 
-igraph_vector_int_e_ptr = _lib.igraph_vector_int_e_ptr
-igraph_vector_int_e_ptr.restype = POINTER(igraph_integer_t)
-igraph_vector_int_e_ptr.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
+igraph_vector_int_get = _lib.igraph_vector_int_get
+igraph_vector_int_get.restype = igraph_integer_t
+igraph_vector_int_get.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
+
+igraph_vector_int_get_ptr = _lib.igraph_vector_int_get_ptr
+igraph_vector_int_get_ptr.restype = POINTER(igraph_integer_t)
+igraph_vector_int_get_ptr.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
 
 igraph_vector_int_push_back = _lib.igraph_vector_int_push_back
 igraph_vector_int_push_back.restype = handle_igraph_error_t
 igraph_vector_int_push_back.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
 
+igraph_vector_int_resize = _lib.igraph_vector_int_resize
+igraph_vector_int_resize.restype = handle_igraph_error_t
+igraph_vector_int_resize.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t]
+
+igraph_vector_int_set = _lib.igraph_vector_int_set
+igraph_vector_int_set.restype = None
+igraph_vector_int_set.argtypes = [POINTER(igraph_vector_int_t), igraph_integer_t, igraph_integer_t]
+
 igraph_vector_int_size = _lib.igraph_vector_int_size
 igraph_vector_int_size.restype = igraph_integer_t
 igraph_vector_int_size.argtypes = [POINTER(igraph_vector_int_t)]
@@ -147,18 +171,30 @@ igraph_vector_bool_view = _lib.igraph_vector_bool_view
 igraph_vector_bool_view.restype = POINTER(igraph_vector_bool_t)
 igraph_vector_bool_view.argtypes = [POINTER(igraph_vector_bool_t), POINTER(igraph_bool_t), igraph_integer_t]
 
-igraph_vector_bool_e = _lib.igraph_vector_bool_e
-igraph_vector_bool_e.restype = igraph_bool_t
-igraph_vector_bool_e.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t]
+igraph_vector_bool_clear = _lib.igraph_vector_bool_clear
+igraph_vector_bool_clear.restype = None
+igraph_vector_bool_clear.argtypes = [POINTER(igraph_vector_bool_t)]
+
+igraph_vector_bool_get = _lib.igraph_vector_bool_get
+igraph_vector_bool_get.restype = igraph_bool_t
+igraph_vector_bool_get.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t]
 
-igraph_vector_bool_e_ptr = _lib.igraph_vector_bool_e_ptr
-igraph_vector_bool_e_ptr.restype = POINTER(igraph_bool_t)
-igraph_vector_bool_e_ptr.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t]
+igraph_vector_bool_get_ptr = _lib.igraph_vector_bool_get_ptr
+igraph_vector_bool_get_ptr.restype = POINTER(igraph_bool_t)
+igraph_vector_bool_get_ptr.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t]
 
 igraph_vector_bool_push_back = _lib.igraph_vector_bool_push_back
 igraph_vector_bool_push_back.restype = handle_igraph_error_t
 igraph_vector_bool_push_back.argtypes = [POINTER(igraph_vector_bool_t), igraph_bool_t]
 
+igraph_vector_bool_resize = _lib.igraph_vector_bool_resize
+igraph_vector_bool_resize.restype = handle_igraph_error_t
+igraph_vector_bool_resize.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t]
+
+igraph_vector_bool_set = _lib.igraph_vector_bool_set
+igraph_vector_bool_set.restype = None
+igraph_vector_bool_set.argtypes = [POINTER(igraph_vector_bool_t), igraph_integer_t, igraph_bool_t]
+
 igraph_vector_bool_size = _lib.igraph_vector_bool_size
 igraph_vector_bool_size.restype = igraph_integer_t
 igraph_vector_bool_size.argtypes = [POINTER(igraph_vector_bool_t)]
@@ -173,14 +209,44 @@ igraph_vector_ptr_destroy = _lib.igraph_vector_ptr_destroy
 igraph_vector_ptr_destroy.restype = None
 igraph_vector_ptr_destroy.argtypes = [c_void_p]
 
+igraph_vector_ptr_clear = _lib.igraph_vector_ptr_clear
+igraph_vector_ptr_clear.restype = None
+igraph_vector_ptr_clear.argtypes = [POINTER(igraph_vector_ptr_t)]
+
 igraph_vector_ptr_get = _lib.igraph_vector_ptr_get
 igraph_vector_ptr_get.restype = c_void_p
 igraph_vector_ptr_get.argtypes = [POINTER(igraph_vector_ptr_t), igraph_integer_t]
 
+igraph_vector_ptr_resize = _lib.igraph_vector_ptr_resize
+igraph_vector_ptr_resize.restype = handle_igraph_error_t
+igraph_vector_ptr_resize.argtypes = [POINTER(igraph_vector_ptr_t), igraph_integer_t]
+
 igraph_vector_ptr_size = _lib.igraph_vector_ptr_size
 igraph_vector_ptr_size.restype = igraph_integer_t
 igraph_vector_ptr_size.argtypes = [POINTER(igraph_vector_ptr_t)]
 
+# String vector type
+
+igraph_strvector_clear = _lib.igraph_strvector_clear
+igraph_strvector_clear.restype = None
+igraph_strvector_clear.argtypes = [POINTER(igraph_strvector_t)]
+
+igraph_strvector_resize = _lib.igraph_strvector_resize
+igraph_strvector_resize.restype = handle_igraph_error_t
+igraph_strvector_resize.argtypes = [POINTER(igraph_strvector_t), igraph_integer_t]
+
+igraph_strvector_set = _lib.igraph_strvector_set
+igraph_strvector_set.restype = handle_igraph_error_t
+igraph_strvector_set.argtypes = [POINTER(igraph_strvector_t), igraph_integer_t, c_char_p]
+
+igraph_strvector_set_len = _lib.igraph_strvector_set_len
+igraph_strvector_set_len.restype = handle_igraph_error_t
+igraph_strvector_set_len.argtypes = [POINTER(igraph_strvector_t), igraph_integer_t, c_char_p, c_size_t]
+
+igraph_strvector_size = _lib.igraph_strvector_size
+igraph_strvector_size.restype = igraph_integer_t
+igraph_strvector_size.argtypes = [POINTER(igraph_strvector_t)]
+
 # Matrix type
 
 igraph_matrix_init = _lib.igraph_matrix_init

src/igraph_ctypes/_internal/attributes.py

@@ -4,10 +4,21 @@
     py_object,
 )
 from dataclasses import dataclass, field
-from typing import Any, Callable, Optional
+from math import nan
+from typing import Any, Callable, MutableMapping, Optional
 
 from .conversion import igraph_vector_int_t_to_numpy_array_view
-from .lib import igraph_error
+from .lib import (
+    igraph_error,
+    igraph_vector_resize,
+    igraph_vector_set,
+    igraph_vector_bool_resize,
+    igraph_vector_bool_set,
+    igraph_vector_int_clear,
+    igraph_strvector_clear,
+    igraph_strvector_resize,
+    igraph_strvector_set,
+)
 from .refcount import incref, decref
 from .types import igraph_attribute_table_t, IntArray
 from .utils import nop, protect_with
@@ -86,6 +97,14 @@ def copy(
         copy_vertex_attributes: bool = True,
         copy_edge_attributes: bool = True,
     ):
+        """Creates a shallow copy of the storage area."""
+        raise NotImplementedError
+
+    @abstractmethod
+    def get_graph_attribute_map(self) -> MutableMapping[str, Any]:
+        """Returns a mutable mapping into the storage area that stores the graph
+        attributes.
+        """
         raise NotImplementedError
 
 
@@ -106,9 +125,6 @@ def add_edges(self, graph, edges: IntArray) -> None:
         pass
 
     def clear(self) -> None:
-        """Clears the storage area, removing all attributes from the
-        attribute dictionaries.
-        """
         self.graph_attributes.clear()
         self.vertex_attributes.clear()
         self.edge_attributes.clear()
@@ -119,13 +135,15 @@ def copy(
         copy_vertex_attributes: bool = True,
         copy_edge_attributes: bool = True,
     ):
-        """Creates a shallow copy of the storage area."""
         return self.__class__(
             self.graph_attributes.copy() if copy_graph_attributes else {},
             self.vertex_attributes.copy() if copy_vertex_attributes else {},
             self.edge_attributes.copy() if copy_edge_attributes else {},
         )
 
+    def get_graph_attribute_map(self) -> MutableMapping[str, Any]:
+        return self.graph_attributes
+
 
 def _assign_storage_to_graph(graph, storage: Optional[AttributeStorage] = None) -> None:
     """Assigns an attribute storage object to a graph, taking care of
@@ -223,7 +241,15 @@ def combine_edges(self, graph, to, mapping, combinations):
         pass
 
     def get_info(self, graph, gnames, gtypes, vnames, vtypes, enames, etypes):
-        pass
+        # TODO(ntamas): fill the names and the types
+        igraph_strvector_clear(gnames)
+        igraph_vector_int_clear(gtypes)
+
+        igraph_strvector_clear(vnames)
+        igraph_vector_int_clear(vtypes)
+
+        igraph_strvector_clear(enames)
+        igraph_vector_int_clear(etypes)
 
     def has_attr(self, graph, type, name) -> bool:
         return False
@@ -232,21 +258,43 @@ def get_type(self, graph, type, elemtype, name):
         pass
 
     def get_numeric_graph_attr(self, graph, name, value):
-        pass
+        vec = value.contents
+        igraph_vector_resize(vec, 1)
+        igraph_vector_set(
+            vec,
+            0,
+            self._to_numeric(
+                _get_storage_from_graph(graph).get_graph_attribute_map()[name]
+            ),
+        )
 
     def get_string_graph_attr(self, graph, name, value):
-        pass
+        vec = value.contents
+        igraph_strvector_resize(vec, 1)
+        igraph_strvector_set(
+            vec,
+            0,
+            self._to_bytes(
+                _get_storage_from_graph(graph).get_graph_attribute_map()[name]
+            ),
+        )
 
-    def get_boolean_graph_attr(self, graph, name, value):
-        pass
+    def get_bool_graph_attr(self, graph, name, value):
+        vec = value.contents
+        igraph_vector_bool_resize(vec, 1)
+        igraph_vector_bool_set(
+            vec,
+            0,
+            bool(_get_storage_from_graph(graph).get_graph_attribute_map()[name]),
+        )
 
     def get_numeric_vertex_attr(self, graph, name, vs, value):
         pass
 
     def get_string_vertex_attr(self, graph, name, vs, value):
         pass
 
-    def get_boolean_vertex_attr(self, graph, name, vs, value):
+    def get_bool_vertex_attr(self, graph, name, vs, value):
         pass
 
     def get_numeric_edge_attr(self, graph, name, es, value):
@@ -255,5 +303,27 @@ def get_numeric_edge_attr(self, graph, name, es, value):
     def get_string_edge_attr(self, graph, name, es, value):
         pass
 
-    def get_boolean_edge_attr(self, graph, name, es, value):
+    def get_bool_edge_attr(self, graph, name, es, value):
         pass
+
+    @staticmethod
+    def _to_bytes(value: Any) -> bytes:
+        """Converts an arbitrary Python object into a byte-level representation,
+        assuming UTF-8 encoding for strings. Returns an empty byte string if the
+        conversion fails.
+        """
+        try:
+            value_str = str(value)
+            return value_str.encode("utf-8", errors="replace")
+        except Exception:
+            return b""
+
+    @staticmethod
+    def _to_numeric(value: Any) -> float:
+        """Converts an arbitrary Python object into a floating-point value,
+        returning NaN if the conversion fails.
+        """
+        try:
+            return float(value)  # type: ignore
+        except Exception:
+            return nan