Update app.py

app.py

@@ -5,5 +5,10 @@ import langcodes
 langtext = st.text_area("language code", "en")
 found = langcodes.find(langtext)
 display = found.display_name()
+
+if tag_is_valid('langtext'):
+  st.write(f"{langtext} is a valid BCP-47 language code")  
+else:
+  st.write(f"{langtext} is not a valid BCP-47 language code")  
 st.write(f"langcodes found the following tag: {found}")
 st.write(f"Display name: {display}")