"Simple" set_fact issue

I am trying to create a list from a set of variables and have some problem doing that.

I must admit I do not understand why it is not easy to manipulate list/dict/vars in Ansible. I must be missing somthing.

So here is my issue:

-set_fact:
my_list: [“abc”] # ok
index: 0 # ok

  • debug: var=my_list[{{index}}] #ok
  • debug: var=public_subnets[0] #ok

-set_fact:
abcd: “{{ my_list[index] }}” #ok
my_list[“{{index}}”]: “abcdefg” # does not work
my_list[0]: “abcdefg” # does not work
my_list.append( “abcdefg”) # does not wokr

is there a way to assign a value to my_list ins the index location or to append to the end of the list