Update logger.py

logger.py

@@ -1,5 +1,6 @@
 import csv
 from datetime import datetime
+import os
 
 def log_feedback(query, rag_context, evo_output, feedback):
     row = {
@@ -10,8 +11,11 @@ def log_feedback(query, rag_context, evo_output, feedback):
         "label": 1 if "👍" in feedback else 0 if "👎" in feedback else "",
     }
 
-    with open("feedback_log.csv", mode="a", newline="", encoding="utf-8") as file:
+    file_path = "feedback_log.csv"
+
+    file_exists = os.path.exists(file_path)
+    with open(file_path, mode="a", newline="", encoding="utf-8") as file:
         writer = csv.DictWriter(file, fieldnames=row.keys())
-        if file.tell() == 0:
+        if not file_exists:
             writer.writeheader()
         writer.writerow(row)