Help for a template sensor error

Configuration
1

I have got this error on startup:

TemplateError(‘TypeError: argument of type ‘NoneType’ is not iterable’)

with the following template

{{states.light 
  | selectattr('entity_id', 'in', state_attr('light.cuisine','entity_id')) 
  | selectattr('state', 'eq', 'on')  
  | list 
  | count 
}}

What’s the way to not have this error please?
tx for answers

2

If you only want the entities in the light group, there’s no reason to start with the state objects of all light entities.

{{ state_attr('light.cuisine','entity_id') 
  | select('is_state', 'on')  
  | list 
  | count }}

If this is being used in a template sensor, you should assign an availability to avoid errors when the light group isn’t available at restart/reload.

3

good lesson
tx very much, all is ok now