python - How to set non-model field property to all the objects in ManyToMany Relation? -

i have django model, manytomany relation, , through recursive function trying set custom property on main model , models in manytomany fields, manytomany related model property not getting reflected templates.

here code snippet:

def update_product_price_details(product):         product.sale_price = product.original_price          if product.product_type == "packaged_product":             product_discount = productservices.get_product_discount(product) # todo : handle multiple items             # calculate product sale price base on subproducts , disocunt             product.original_price  = 0             sub_product  in product.packagedproduct.sub_products.all():                 sub_product = productservices.update_product_price_details(sub_product)                 product.original_price = product.original_price + sub_product.sale_price              if product_discount , product_discount.is_valid():                 product.sale_price = product.original_price - (product.original_price*product_discount.discount_percentage/100)          else:             product_discount = productservices.get_product_discount(product) # todo : handle multiple items             # if valid discount set new price sale_price             if product_discount , product_discount.is_valid():                 product.sale_price = product.original_price - (product.original_price*product_discount.discount_percentage/100)          return product 

code explanation

i pass product model update_product_price_details(product) , each sub product calculating sale_price, calculate pacakged_product sale_price.

sub_product = productservices.update_product_price_details(sub_product) 

the value setting sub_product via above line of code not reflected actual product model.

is there way update manytomany field model custom property? totally stuck here, please help.

many many thanks.

making use of model functions simple solution it, nice , clean.