5_compatibility.py

from typing import TypedDict


# few keys
class Movie(TypedDict):
    name: str
    year: int


# more keys
class BookBasedMovie(TypedDict):
    name: str
    year: int
    based_on: str


def print_movie(movie: Movie) -> None:
    print(f"{movie['name']} ({movie['year']})")


def print_book_movie(movie: BookBasedMovie) -> None:
    print(f"{movie['name']} ({movie['year']}) {movie["based_on"]}")


book_movie: BookBasedMovie = {
    "name": "Dune",
    "year": 2021,
    "based_on": "Dune by Frank Herbert",
}
movie: Movie = {"name": "Dune", "year": 2021}

#Argument of type "Movie" cannot be assigned 
# to parameter "movie" of type "BookBasedMovie" in function "print_book_movie"
# "based_on" is missing from "Movie"
# As you can see the function argument defined "movie" of type defined as 
# "BookBasedMovie" is missing attribute called "based_on"
# "BookBasedMovie" and "Movie" difference by one additional attribute called 
# "based_one"
print_book_movie(movie)  # Error


print_movie(book_movie)  # OK