Update app.py

app.py

@@ -31,9 +31,10 @@ def generate_df():
    
 @st.cache_data()
 def write_df(df, file, cls):
-    rec = {'Image file name': file,
+    rec = {'Image file name': file.name,
            'Class name': cls}
-    df.append(rec, ignore_index = True)
+    df = pd.concat([df, pd.DataFrame([rec])], ignore_index=True)
+    return df
 
 @st.cache_data()
 def convert_df(df):