if "optional_key" in my_dict: do_something_with(my_dict["optional_key"])
optional_value = my_dict.get("optional_key") if optional_value: do_something_with(optional value)
my_dict.get("optional_parent", {}).get("optional_child")
If you have a dict with some keys which are optional, you need to create a separate subclass (with `total=False`) just for those optional keys.
With TypeScript, I can just use `key?: type`.
https://mypy.readthedocs.io/en/latest/more_types.html#mixing...