Add example of catalog copying into MovieLister example

examples/stories/movie_lister/apps_db_csv.py

@@ -0,0 +1,76 @@
+"""A naive example of dependency injection in Python.
+
+Example implementation of dependency injection in Python from Martin Fowler's
+article about dependency injection and inversion of control:
+
+http://www.martinfowler.com/articles/injection.html
+
+This mini application uses ``movies`` library, that is configured to work with
+csv file movies database.
+"""
+
+import sqlite3
+
+from dependency_injector import catalogs
+from dependency_injector import providers
+from dependency_injector import injections
+
+from movies import MoviesModule
+from movies import finders
+
+from settings import MOVIES_CSV_PATH
+from settings import MOVIES_DB_PATH
+
+
+class ApplicationModule(catalogs.DeclarativeCatalog):
+    """Catalog of application component providers."""
+
+    database = providers.Singleton(sqlite3.connect, MOVIES_DB_PATH)
+
+
+@catalogs.copy(MoviesModule)
+class DbMoviesModule(MoviesModule):
+    """Customized catalog of movies module component providers."""
+
+    movie_finder = providers.Factory(finders.SqliteMovieFinder,
+                                     *MoviesModule.movie_finder.injections,
+                                     database=ApplicationModule.database)
+
+
+@catalogs.copy(MoviesModule)
+class CsvMoviesModule(MoviesModule):
+    """Customized catalog of movies module component providers."""
+
+    movie_finder = providers.Factory(finders.CsvMovieFinder,
+                                     *MoviesModule.movie_finder.injections,
+                                     csv_file=MOVIES_CSV_PATH,
+                                     delimeter=',')
+
+
+@injections.inject(db_movie_lister=DbMoviesModule.movie_lister)
+@injections.inject(csv_movie_lister=CsvMoviesModule.movie_lister)
+def main(db_movie_lister, csv_movie_lister):
+    """Main function.
+
+    This program prints info about all movies that were directed by different
+    persons and then prints all movies that were released in 2015.
+
+    :param db_movie_lister: Database movie lister instance
+    :type db_movie_lister: movies.listers.MovieLister
+
+    :param csv_movie_lister: Database movie lister instance
+    :type csv_movie_lister: movies.listers.MovieLister
+    """
+    print db_movie_lister.movies_directed_by('Francis Lawrence')
+    print db_movie_lister.movies_directed_by('Patricia Riggen')
+    print db_movie_lister.movies_directed_by('JJ Abrams')
+    print db_movie_lister.movies_released_in(2015)
+
+    print csv_movie_lister.movies_directed_by('Francis Lawrence')
+    print csv_movie_lister.movies_directed_by('Patricia Riggen')
+    print csv_movie_lister.movies_directed_by('JJ Abrams')
+    print csv_movie_lister.movies_released_in(2015)
+
+
+if __name__ == '__main__':
+    main()