ค้นหาจำนวนคุณลักษณะที่ผลิตภัณฑ์ "ผ้าลินิน" มี
Find the number of characteristics that the product "flax" has.
df_characteristics = pd.DataFrame(columns=['characteristic_id'])
df_products = pd.DataFrame(columns=['product_id', 'product_name'])
df_product_characteristics = pd.DataFrame(columns=['product_id', 'characteristic_id'])
df_product_characteristics['product_id'].value_counts()[df_products[df_products['product_name'] == 'flax']['product_id'].values[0]]