Fix BranchTee ID setting if its the first BT in the grid

openego · Oct 26, 2017 · f7a1bde · f7a1bde
1 parent 3fdfaa5
commit f7a1bde
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/edisgo/grid/components.py b/edisgo/grid/components.py
@@ -440,8 +440,12 @@ def __init__(self, **kwargs):
 
         # set id of BranchTee automatically if not provided
         if not self._id:
-            self._id = max([_.id for _ in
-                            self.grid.graph.nodes_by_attribute('branch_tee')]) + 1
+            ids = [_.id for _ in
+                            self.grid.graph.nodes_by_attribute('branch_tee')]
+            if ids:
+                self._id = max(ids) + 1
+            else:
+                self._id = 1
 
     def __repr__(self):
         return '_'.join([self.__class__.__name__, repr(self.grid), str(self._id)])