Update app.py

app.py

@@ -728,7 +728,7 @@ def translate(txt,to_lang="en",from_lang=False):
         words = txt.split()
         while len(words) > 0:
             chunk = ""
-            while len(chunk) < 490:
+            while len(words) > 0 and len(chunk) < 490:
                 chunk = chunk + " " + words[0]
                 words = words[1:]
             if len(chunk) > 490: