diff --git a/trlx/pipeline/ppo_pipeline.py b/trlx/pipeline/ppo_pipeline.py
index 19bae03af..2b1ea374e 100644
--- a/trlx/pipeline/ppo_pipeline.py
+++ b/trlx/pipeline/ppo_pipeline.py
@@ -84,7 +84,7 @@ def filter_text(d, only_text):
                         d.pop(key)
             return d
 
-        data = [filter_text(exp_to_dict(exp), only_text) for exp in self.history]      
+        data = [filter_text(exp_to_dict(exp), only_text) for exp in self.history]
         with open(fpath, "w") as f:
             f.write(json.dumps(data, indent=2))