Update app.py

app.py

@@ -54,6 +54,10 @@ def infer(
     width = max(256, (width // 8) * 8)
     height = max(256, (height // 8) * 8)
 
+    # Set default value if num_inference_steps is None
+    if num_inference_steps is None:
+        num_inference_steps = 20
+
     generator = torch.Generator().manual_seed(seed)
 
     image = pipe(