diff --git a/trajectories.py b/trajectories.py
index 1634a7434e0b2b52d22d9af90d5869259fd7235b..113c9a13f09baa46c2e410b3a03bfddef32e14a8 100755
--- a/trajectories.py
+++ b/trajectories.py
@@ -42,27 +42,28 @@ print('Setting trajectory vertex property...')
 
 for edge in g.edges():
     current_cf = g.ep.cost_function[edge]
-    src = edge.source()
-    trg = edge.target()
+    source = edge.source()
+    target = edge.target()
 
-    if src.out_degree() > 1:
+    if source.out_degree() > 1:
         # Source is a split
-        if current_cf <= min({g.ep.cost_function[e] for e in src.out_edges()}):
-            if trg.in_degree() > 1:
+        if current_cf <= min({g.ep.cost_function[e]
+                              for e in source.out_edges()}):
+            if target.in_degree() > 1:
                 if current_cf <= min({g.ep.cost_function[e]
-                                      for e in trg.out_edges()}):
-                    # Set trg trajectory to src trajectory
-                    traj_prop[trg] = traj_prop[src]
+                                      for e in target.out_edges()}):
+                    # Set target trajectory to source trajectory
+                    traj_prop[target] = traj_prop[source]
             else:
-                traj_prop[trg] = traj_prop[src]
+                traj_prop[target] = traj_prop[source]
     else:
-        # src.out_degree() == 1
-        if trg.in_degree() > 1:
+        # source.out_degree() == 1
+        if target.in_degree() > 1:
             if current_cf <= min({g.ep.cost_function[e]
-                                  for e in trg.in_edges()}):
-                traj_prop[trg] = traj_prop[src]
+                                  for e in target.in_edges()}):
+                traj_prop[target] = traj_prop[source]
         else:
-            traj_prop[trg] = traj_prop[src]
+            traj_prop[target] = traj_prop[source]
 
 print('Creating the dictionary of trajectories...')
 visitor = Visitor()