pep8: Fix code format for model.

src/Model/Network/Edge.py

@@ -75,7 +75,10 @@ class Edge(object):
 
     @property
     def name(self):
-        return self._name if self._name != "" else f"{self.node1.name} -> {self.node2.name}"
+        name = self._name
+        if self._name == "":
+            name = f"{self.node1.name} -> {self.node2.name}"
+        return name
 
     def is_enable(self):
         return self._enable