first step to self loops

zxcalc · Jun 26, 2024 · c7e62f6 · c7e62f6
1 parent 32f7ef7
commit c7e62f6
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/pyzx/graph/multigraph.py b/pyzx/graph/multigraph.py
@@ -209,7 +209,7 @@ def remove_vertices(self, vertices):
                 e = self.graph[v][v1]
                 self.nedges -= e.s + e.h
                 del self.graph[v][v1]
-                del self.graph[v1][v]
+                if v != v1: del self.graph[v1][v]
             # remove the vertex
             del self.graph[v]
             del self.ty[v]
@@ -270,7 +270,7 @@ def edges(self, s=None, t=None):
         if s == None:
             for v0,adj in self.graph.items():
                 for v1, e in adj.items():
-                    if v1 > v0:
+                    if v1 >= v0:
                         for _ in range(e.s): yield (v0, v1, EdgeType.SIMPLE)
                         for _ in range(e.h): yield (v0, v1, EdgeType.HADAMARD)
                         for _ in range(e.w_io): yield (v0, v1, EdgeType.W_IO)