Django @override_settings does not allow dictionary?

Question

I am new to Python decorators so perhaps I am missing something simple, here is my situation:

This works for me:

def test_something(self):
    settings.SETTING_DICT['key'] = True #no error
    ...

But this throws a "SyntaxError: keyword can't be an expression":

@override_settings(SETTING_DICT['key'] = True) #error
def test_something(self):
   ...

Just to be clear, normal use of override settings works:

@override_settings(SETTING_VAR = True) #no error
def test_something(self):
   ...

Is there a way to use the decorator with a settings dictionary, or am I doing something wrong?

Thanks in advance!

Answer 1

You should override the whole dict:

@override_settings(SETTING_DICT={'key': True})
def test_something(self):
   ...

Or, you can use override_settings as a context manager:

def test_something(self):
     value = settings.SETTING_DICT
     value['key'] = True
     with override_settings(SETTING_DICT=value):
         ...

Answer 2

I didn't want to override the whole dict either, so I copied the dictionary in question from the settings object and just modified the attribute I was interested in:

import copy
from django.conf import settings

settings_dict = deepcopy(settings.SETTINGS_DICT)
settings_dict['key1']['key2'] = 'new value'

@override_settings(SETTINGS_DICT=settings_dict)
def test_something(self):
    pass

It suits my purposes, but if you wanted to make this more widely usable, you could write a short function with a few arguments which could do something like this dynamically.

Note: I tried using settings.SETTINGS_DICT.copy() instead of deepcopy(settings.SETTINGS_DICT) but that seemed to globally override the setting for all tests...