voluptatem ของผลิตภัณฑ์มีปัญหากี่ข้อ?
How many problems are there for product voluptatem?
df1 = pd.DataFrame({'product_id': []}); df2 = pd.DataFrame({'product_id': [], 'product_name': []})
df1.merge(df2[df2['product_name'] == 'voluptatem'], on = 'product_id').shape[0]