how to store a dictionary within a for loop

Question

I want to store the values of data in a dictionary my dict{} but i got an error.

mydict= {}
for entity in entities:
     if entity.entity_id.startswith('sensor'):
         list = remote.get_state(api, entity.entity_id)
         data = {list.attributes['friendly_name'] : list.state}
         for key, val in data.items():
             mydict+= {key:val}

I got the following Error.

mydict+= {key:val}
TypeError: unsupported operand type(s) for +=: 'dict' and 'dict'

Answer 1

Contrary to one may intuitively think, as the error indicates, += operator is not supported for types dict & dict. Dictionaries are a little different than lists, and += does not work like some sort of concatenation operator for them.

However, instead of using += operator, why don't you try updating the inner for loop scope as done in the following snippet?

mydict= {}
for entity in entities:
    if entity.entity_id.startswith('sensor'):
        list = remote.get_state(api, entity.entity_id)
        data = {list.attributes['friendly_name'] : list.state}
        for key, val in data.items():
            mydict[key] = val

Alternatively, you can do a bulk update, as given below.

mydict= {}
for entity in entities:
    if entity.entity_id.startswith('sensor'):
        list = remote.get_state(api, entity.entity_id)
        data = {list.attributes['friendly_name'] : list.state}
        mydict.update(data)