สินค้าตัวไหนถูกสั่งบ่อยที่สุด?
Which product has been ordered most number of times?
df_products = pd.DataFrame(columns=['product_details', 'product_id']); df_order_items = pd.DataFrame(columns=['product_id'])
df_products.loc[df_products['product_id'] == df_order_items['product_id'].value_counts().idxmax()]['product_details']