merge all-branches branch

Signed-off-by: Thijs Baaijen <13253091+Thijss@users.noreply.github.com>

Author: Thijss

src/power_grid_model_ds/_core/model/graphs/models/base.py

@@ -36,6 +36,13 @@ def nr_nodes(self):
     def nr_branches(self):
         """Returns the number of branches in the graph"""
 
+    @property
+    @abstractmethod
+    def all_branches(self) -> list[frozenset[int]]:
+        """Returns all branches in the graph as a list of node pairs (frozensets).
+        Warning: Depending on graph engine, performance could be slow for large graphs
+        """
+
     @abstractmethod
     def external_to_internal(self, ext_node_id: int) -> int:
         """Convert external node id to internal node id (internal)

src/power_grid_model_ds/_core/model/graphs/models/rustworkx.py

@@ -32,6 +32,15 @@ def nr_nodes(self):
     def nr_branches(self):
         return self._graph.num_edges()
 
+    @property
+    def all_branches(self) -> list[frozenset[int]]:
+        internal_branches = ((source, target) for source, target in self._graph.edge_list())
+        external_branches = [
+            frozenset([self.internal_to_external(source), self.internal_to_external(target)])
+            for source, target in internal_branches
+        ]
+        return external_branches
+
     @property
     def external_ids(self) -> list[int]:
         return list(self._external_to_internal.keys())

tests/unit/model/graphs/test_graph_model.py

@@ -37,6 +37,24 @@ def test_graph_has_branch(graph):
     assert not graph.has_branch(1, 3)
 
 
+def test_graph_all_branches(graph):
+    graph.add_node(1)
+    graph.add_node(2)
+    graph.add_branch(1, 2)
+
+    assert [{1, 2}] == graph.all_branches
+
+
+def test_graph_all_branches_parallel(graph):
+    graph.add_node(1)
+    graph.add_node(2)
+    graph.add_branch(1, 2)
+    graph.add_branch(1, 2)
+    graph.add_branch(2, 1)
+
+    assert [{1, 2}, {1, 2}, {1, 2}] == graph.all_branches
+
+
 def test_graph_delete_branch(graph):
     """Test whether a branch is deleted correctly"""
     graph.add_node(1)