Calculate fields in view and pass the query to the template

I am using Django 1.4 and I have a query that brings several data from the db, including one that can have 3 different values (type). Depending on this data I make a conditional and calculate some values (accommodation and diet) to send to the template. If I do it with only one line in the data it works well, the problem is when I have several lines in which if I respect the data that comes in the recordset (name, date and type) but in the fields that calculates puts me in all lines the same.

This is what I want.

nombre        tipo mes     alojamiento        dieta
nombre_1       1   enero   50                 45
nombre_2       2   febrero 60                 80

Where:

• accommodation = days * amount_hotel --- days depend on type.
• diets = days * amount_diet ---- the two values depend on the type.

This is what I have.

nombre        tipo mes     importe_noche importe_dieta
nombre_1       1   enero   60                 80
nombre_2       2   febrero 60                 80

I've tried it with aggregate , but it gives me an error because the data to be calculated is not in the database.