Add draft version of MovieLister example

examples/stories/movie_lister/_create_db.py

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+"""Small script for initializing movies data."""
+
+import os
+import csv
+import sqlite3
+import shutil
+
+from settings import DATA_DIR
+from settings import MOVIES_CSV_PATH
+from settings import MOVIES_DB_PATH
+
+
+MOVIES = (('The Hunger Games: Mockingjay - Part 2', 2015, 'Francis Lawrence'),
+          ('The 33', 2015, 'Patricia Riggen'),
+          ('Star Wars: Episode VII - The Force Awakens', 2015, 'JJ Abrams'))
+
+
+if __name__ == '__main__':
+    # (Re)create data directory:
+    if os.path.exists(DATA_DIR):
+        shutil.rmtree(DATA_DIR)
+    os.makedirs(DATA_DIR)
+
+    # Initialize sqlite database:
+    connection = sqlite3.connect(MOVIES_DB_PATH)
+    with connection:
+        connection.execute('CREATE TABLE movies '
+                           '(name text, year int, director text)')
+        connection.executemany('INSERT INTO movies VALUES (?,?,?)', MOVIES)
+
+    # Initialize csv database:
+    with open(MOVIES_CSV_PATH, 'w') as csv_file:
+        csv.writer(csv_file).writerows(MOVIES)

examples/stories/movie_lister/app_csv.py

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+"""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
+"""
+
+from movies.module import MoviesModule
+from movies.components import CsvMovieFinder
+
+from settings import MOVIES_CSV_PATH
+
+from dependency_injector import catalogs
+from dependency_injector import providers
+
+
+@catalogs.override(MoviesModule)
+class MyMoviesModule(catalogs.DeclarativeCatalog):
+    """Customized catalog of movie module components."""
+
+    movie_finder = providers.Factory(CsvMovieFinder,
+                                     csv_file=MOVIES_CSV_PATH,
+                                     delimeter=',')
+
+
+def main():
+    """Main function."""
+    movie_lister = MoviesModule.movie_lister()
+
+    print movie_lister.movies_directed_by('Francis Lawrence')
+    print movie_lister.movies_directed_by('Patricia Riggen')
+    print movie_lister.movies_directed_by('JJ Abrams')
+
+    print movie_lister.movies_released_in(2015)
+
+
+if __name__ == '__main__':
+    main()

examples/stories/movie_lister/app_db.py

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+"""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
+"""
+
+import sqlite3
+
+from movies.module import MoviesModule
+from movies.components import SqliteMovieFinder
+
+from settings import MOVIES_DB_PATH
+
+from dependency_injector import catalogs
+from dependency_injector import providers
+
+
+class ApplicationModule(catalogs.DeclarativeCatalog):
+    """Catalog of application components."""
+
+    database = providers.Singleton(sqlite3.connect,
+                                   MOVIES_DB_PATH)
+    """:type: providers.Provider -> components.MovieFinder"""
+
+
+@catalogs.override(MoviesModule)
+class MyMoviesModule(catalogs.DeclarativeCatalog):
+    """Customized catalog of movie module components."""
+
+    movie_finder = providers.Factory(SqliteMovieFinder,
+                                     database=ApplicationModule.database)
+
+
+def main():
+    """Main function."""
+    movie_lister = MoviesModule.movie_lister()
+
+    print movie_lister.movies_directed_by('Francis Lawrence')
+    print movie_lister.movies_directed_by('Patricia Riggen')
+    print movie_lister.movies_directed_by('JJ Abrams')
+
+    print movie_lister.movies_released_in(2015)
+
+
+if __name__ == '__main__':
+    main()

examples/stories/movie_lister/data/.gitignore

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+movies.*

examples/stories/movie_lister/movies/__init__.py

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+"""Movies package."""

examples/stories/movie_lister/movies/components.py

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+"""Movies package components."""
+
+import csv
+
+
+class MovieLister(object):
+    """Movie lister."""
+
+    def __init__(self, movie_finder):
+        """Initializer."""
+        self.movie_finder = movie_finder
+
+    def movies_directed_by(self, director):
+        """Return list of movies that were directed by certain person.
+
+        :param director: Director's name
+        :type director: str
+
+        :rtype: list[:py:class:`Movie`]
+        :return: List of movie instances.
+        """
+        return [movie for movie in self.movie_finder.find_all()
+                if movie.director == director]
+
+    def movies_released_in(self, year):
+        """Return list of movies that were released in certain year.
+
+        :param year: Release year
+        :type year: int
+
+        :rtype: list[:py:class:`Movie`]
+        :return: List of movie instances.
+        """
+        return [movie for movie in self.movie_finder.find_all()
+                if movie.year == year]
+
+
+class MovieFinder(object):
+    """Movie finder."""
+
+    def find_all(self):
+        """Return all found movies.
+
+        :rtype: list[:py:class:`Movie`]
+        :return: List of movie instances.
+        """
+        raise NotImplementedError()
+
+
+class CsvMovieFinder(MovieFinder):
+    """Movie finder that fetches movies info from csv file."""
+
+    def __init__(self, csv_file, delimeter):
+        """Initializer."""
+        self.csv_file = csv_file
+        self.delimeter = delimeter
+
+    def find_all(self):
+        """Return all found movies.
+
+        :rtype: list[:py:class:`Movie`]
+        :return: List of movie instances.
+        """
+        with open(self.csv_file) as csv_file:
+            reader = csv.reader(csv_file, delimiter=self.delimeter)
+            return [Movie(*row) for row in reader]
+
+
+class SqliteMovieFinder(MovieFinder):
+    """Movie finder that fetches movies info from sqlite database."""
+
+    def __init__(self, database):
+        """Initializer."""
+        self.database = database
+
+    def find_all(self):
+        """Return all found movies.
+
+        :rtype: list[:py:class:`Movie`]
+        :return: List of movie instances.
+        """
+        with self.database:
+            rows = self.database.execute('SELECT name, year, director '
+                                         'FROM movies')
+            return [Movie(*row) for row in rows]
+
+
+class Movie(object):
+    """Movie model."""
+
+    def __init__(self, name, year, director):
+        """Initializer."""
+        self.name = str(name)
+        self.year = int(year)
+        self.director = str(director)
+
+    def __repr__(self):
+        """Return string representation of movie instance."""
+        return 'Movie(name={0}, year={1}, director={2})'.format(
+            repr(self.name), repr(self.year), repr(self.director))

examples/stories/movie_lister/movies/module.py

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+"""Movies package dependency injection module."""
+
+from . import components
+
+from dependency_injector import catalogs
+from dependency_injector import providers
+
+
+class MoviesModule(catalogs.DeclarativeCatalog):
+    """Catalog of movie module components."""
+
+    movie_finder = providers.Factory(components.MovieFinder)
+    """:type: providers.Provider -> components.MovieFinder"""
+
+    movie_lister = providers.Factory(components.MovieLister,
+                                     movie_finder=movie_finder)
+    """:type: providers.Provider -> components.MovieLister"""

examples/stories/movie_lister/settings.py

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+"""Settings module.
+
+This module contains application's settings and constants.
+"""
+
+import os
+
+
+DATA_DIR = os.path.abspath(os.path.dirname(__file__) + '/data')
+
+MOVIES_CSV_PATH = DATA_DIR + '/movies.csv'
+MOVIES_CSV_DELIMETER = ','
+
+MOVIES_DB_PATH = DATA_DIR + '/movies.db'