merge all_branches

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

Author: Thijss

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

@@ -3,7 +3,6 @@
 # SPDX-License-Identifier: MPL-2.0
 
 from abc import ABC, abstractmethod
-from contextlib import contextmanager
 from typing import Generator
 
 import numpy as np
@@ -37,11 +36,12 @@ 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
-        """
+    def all_branches(self) -> Generator[tuple[int, int], None, None]:
+        """Returns all branches in the graph."""
+        return (
+            (self.internal_to_external(source), self.internal_to_external(target))
+            for source, target in self._all_branches()
+        )
 
     @abstractmethod
     def external_to_internal(self, ext_node_id: int) -> int:
@@ -348,6 +348,9 @@ def _get_components(self, substation_nodes: list[int]) -> list[list[int]]: ...
     @abstractmethod
     def _find_fundamental_cycles(self) -> list[list[int]]: ...
 
+    @abstractmethod
+    def _all_branches(self) -> Generator[tuple[int, int], None, None]: ...
+
 
 def _get_branch3_branches(branch3: Branch3Array) -> BranchArray:
     node_1 = branch3.node_1.item()

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

@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: MPL-2.0
 
 import logging
+from typing import Generator
 
 import rustworkx as rx
 from rustworkx import NoEdgeBetweenNodes
@@ -119,6 +120,9 @@ def _find_fundamental_cycles(self) -> list[list[int]]:
         """
         return find_fundamental_cycles_rustworkx(self._graph)
 
+    def _all_branches(self) -> Generator[tuple[int, int], None, None]:
+        return ((source, target) for source, target in self._graph.edge_list())
+
 
 class _NodeVisitor(BFSVisitor):
     def __init__(self, nodes_to_ignore: list[int]):

tests/unit/model/graphs/test_graph_model.py

@@ -44,7 +44,7 @@ def test_graph_all_branches(graph):
     graph.add_node(2)
     graph.add_branch(1, 2)
 
-    assert [{1, 2}] == graph.all_branches
+    assert [(1, 2)] == list(graph.all_branches)
 
 
 def test_graph_all_branches_parallel(graph):
@@ -54,7 +54,7 @@ def test_graph_all_branches_parallel(graph):
     graph.add_branch(1, 2)
     graph.add_branch(2, 1)
 
-    assert [{1, 2}, {1, 2}, {1, 2}] == graph.all_branches
+    assert [(1, 2), (1, 2), (2, 1)] == list(graph.all_branches)
 
 
 def test_graph_delete_branch(graph):