Fix f-string format specifier error in logging callback

train.py

@@ -104,10 +104,13 @@ class VerboseLoggingCallback(TrainerCallback):
         loss = logs.get("loss", "N/A")
         lr = logs.get("learning_rate", "N/A")
 
+        loss_str = f"{loss:.4f}" if isinstance(loss, float) else str(loss)
+        lr_str = f"{lr:.2e}" if isinstance(lr, float) else str(lr)
+
         print(f"[{datetime.now().strftime('%H:%M:%S')}] "
               f"Step {state.global_step}/{state.max_steps} ({progress:.1f}%) | "
-              f"Loss: {loss:.4f if isinstance(loss, float) else loss} | "
-              f"LR: {lr:.2e if isinstance(lr, float) else lr} | "
+              f"Loss: {loss_str} | "
+              f"LR: {lr_str} | "
               f"Elapsed: {elapsed_str} | ETA: {eta_str}")
 
         # GPU メモリ使用量（10ステップごと）