Update app.py

app.py

@@ -1,6 +1,7 @@
 import gradio as gr
 import subprocess
 
+
 def fn(txt):
     command = ["python", "-u", "script.py"]
     process = subprocess.Popen(
@@ -10,6 +11,9 @@ def fn(txt):
         universal_newlines=True,
     )
 
+    if process.stdout is None:
+        raise ValueError("stdout is None")
+
     for line in process.stdout:
         yield txt + line
 
@@ -18,6 +22,9 @@ def fn(txt):
     if return_code:
         raise subprocess.CalledProcessError(return_code, command)
 
+
 with gr.Blocks() as demo:
     txt = gr.Code()
-    demo.load(fn, inputs=txt, outputs=txt)
+    demo.load(fn, inputs=txt, outputs=txt)
+
+demo.launch()