Update cord_inference.py

cord_inference.py

@@ -64,7 +64,7 @@ def prediction(image):
         else:
             d[i] = d[i] + ", " + true_words[id]
     d = {k: v.strip() for (k, v) in d.items()}
-    d.pop("O")
+    if "O" in d: d.pop("O")
 
     # TODO:process the json