How can I manually modify models retrieved from the database in Django? -

i wish such following:

people = people.objects.filter(date=date) person = people[0] person['salary'] = 45000 

the last line results in error:

object not support item assignment 

to debug find easier start working , modify line line until breaks.

i want modify object rendering in template. if try:

person.salary = 45000 

there no error trying

print person.salary 

immediately afterwards results in original value being printed. update:

in code doing:

people[0].salary = 45000 

which doesn't work. reason

person = people[0] person.salary = 45000 

does work. thought 2 pieces of code same

looking @ ids, seems when assign entry variable, copy, not original reference:

in [11]: people = people.objects.filter(salary=100) in [12]: person = people[0] in [13]: person.salary = 5000 in [14]: print person.salary 5000 in [15]: people[0].salary out[15]: 100 in [16]: id(people[0]) out[16]: 35312400 in [17]: id(person) out[17]: 35313104 

so, let's @ happens in depth. know in django querysets evaluated when need results (lazy evaluation). quote the django documentation:

slicing. explained in limiting querysets, queryset can sliced, using python’s array-slicing syntax. slicing unevaluated queryset returns unevaluated queryset, django execute database query if use “step” parameter of slice syntax, , return list. slicing queryset has been evaluated (partially or fully) returns list.

in particular, looking @ 'django.db.models.query' source code,

    def __getitem__(self, k):     """     retrieves item or slice set of results.     """     # stuff here ...      if isinstance(k, slice):         qs = self._clone()         if k.start not none:             start = int(k.start)         else:             start = none         if k.stop not none:             stop = int(k.stop)         else:             stop = none         qs.query.set_limits(start, stop)         return k.step , list(qs)[::k.step] or qs      qs = self._clone()     qs.query.set_limits(k, k + 1)     return list(qs)[0] 

you can see when use slicing, calling __getitem__ method. self._clone method provide different instance of same queryset. reason getting different results.