pycharm code completion for objects retrieved from constructed dictionary

Question

I have number of similar objects, and want to use dict as mapping to get the desired one, i.e.

from typing import NamedTuple
NT= NamedTuple("test", param_a=int) # more complex
nt1 = NT(param_a=1)
nt2 = NT(param_a=2)
my_dict={1:nt1, 2:nt2} #based on key, my_dict will 'return' desired namedtuple

manually stating all key value pairs like above would allow code completion when using my_dict with parameter to represent the key

key = 1 # just to illustrate,actually will be computed or provided by user
my_dict[key].  # code completion does work here, after pressing dot '.' I'm offered param_a

However if the dict is constructed via comprehension code completion does not work

my_dict = { x.param_a:x for x in [nt1,nt2] } # key construction will be complex, also I may have numerous namedtuples, hence using dict comprehension to build my_dict 
key= 1
my_dict[key]. # code completion does NOT work anymore

How can I achieve code completion for constructed dict? I realize primitive hack could be just temporarily include my_dict={1:nt} just to allow writing further code with code completion enabled, however I'd have to add this (and remember to remove!) everytime I'd like to make change with code completion