Fix legacy callback.

dmlc · Oct 30, 2020 · 40b5562 · 40b5562
1 parent c9ddda0
commit 40b5562
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/python-package/xgboost/callback.py b/python-package/xgboost/callback.py
@@ -692,9 +692,11 @@ def __init__(self, callbacks, start_iteration, end_iteration,
 
     def before_training(self, model):
         '''Nothing to do for legacy callbacks'''
+        return model
 
     def after_training(self, model):
         '''Nothing to do for legacy callbacks'''
+        return model
 
     def before_iteration(self, model, epoch, dtrain, evals):
         '''Called before each iteration.'''