How to use the castero.datafile.DataFile function in castero

def test_datafile_download(display):
    display.change_status = mock.MagicMock(name="change_status")
    mydownloadqueue = DownloadQueue()
    url = "https://travis-ci.org/"
    DataFile.download_to_file(
        url,
        "datafile_download_temp",
        "datafile download name",
        mydownloadqueue,
        display=display
    )
    while mydownloadqueue.length > 0:
        pass
    assert display.change_status.call_count > 0
    assert os.path.exists("datafile_download_temp")
    os.remove("datafile_download_temp")

def test_datafile_download_bad_url(display):
    display.change_status = mock.MagicMock(name="change_status")
    mydownloadqueue = DownloadQueue()
    url = "https://bad"
    DataFile.download_to_file(
        url,
        "datafile_download_temp",
        "datafile download name",
        mydownloadqueue,
        display=display
    )
    while mydownloadqueue.length > 0:
        pass
    assert display.change_status.call_count > 0
    assert not os.path.exists("datafile_download_temp")

def test_episode_playable_local():
    DataFile.DEFAULT_DOWNLOADED_DIR = os.path.join(my_dir, "downloaded")
    myfeed = Feed(file=my_dir + "/feeds/valid_basic.xml")
    episode = myfeed.parse_episodes()[0]
    playable = episode.get_playable()
    assert episode.downloaded
    assert playable == os.path.join(DataFile.DEFAULT_DOWNLOADED_DIR,
                                    "myfeed_title",
                                    "myfeed_item1_title.mp3")

    DataFile.DEFAULT_DOWNLOADED_DIR = os.path.join(DataFile.DATA_DIR,
                                                   "downloaded")

class Database():
    """The user's database.

    This class provides an API for storing and retrieving data from an sqlite
    database file.

    The database replaces the Feeds class which stored feed/episode data in a
    JSON file. We automatically migrate users from that format to the database:
    see _create_from_old_feeds().

    For schema details, see $PACKAGE/templates/migrations.
    """
    PATH = os.path.join(DataFile.DATA_DIR, 'castero.db')
    OLD_PATH = os.path.join(DataFile.DATA_DIR, 'feeds')
    MIGRATIONS_DIR = os.path.join(DataFile.PACKAGE, 'templates/migrations')

    SQL_EPISODES_BY_ID = "select feed_key, id, title, description, link, pubdate, copyright, enclosure, played from episode where id=?"
    SQL_EPISODES_BY_FEED = "select id, title, description, link, pubdate, copyright, enclosure, played from episode where feed_key=?"
    SQL_EPISODE_REPLACE = "replace into episode (id, title, feed_key, description, link, pubdate, copyright, enclosure, played)\nvalues (?,?,?,?,?,?,?,?,?)"
    SQL_EPISODE_REPLACE_NOID = "replace into episode (title, feed_key, description, link, pubdate, copyright, enclosure, played)\nvalues (?,?,?,?,?,?,?,?)"
    SQL_FEEDS_ALL = "select key, title, description, link, last_build_date, copyright from feed"
    SQL_FEED_BY_KEY = "select key, title, description, link, last_build_date, copyright from feed where key=?"
    SQL_FEED_REPLACE = "replace into feed (key, title, description, link, last_build_date, copyright)\nvalues (?,?,?,?,?,?)"
    SQL_FEED_DELETE = "delete from feed where key=?"
    SQL_QUEUE_ALL = "select id, ep_id from queue"
    SQL_QUEUE_REPLACE = "replace into queue (id, ep_id)\nvalues (?,?)"
    SQL_QUEUE_DELETE = "delete from queue"

    def __init__(self):
        """

class ConfigDuplicateError(ConfigError):
    """The config file contained a duplicate variable.
    """


class _Config(DataFile):
    """The user's config settings.

    Reads the configuration file. Instances of this class can generally be
    treated like dictionaries, accessing a variable with config_instance[key].

    Modifying config variables inside the application is not supported; config
    changes must be made to the config file itself.
    """
    PATH = os.path.join(DataFile.CONFIG_DIR, 'castero.conf')
    DEFAULT_PATH = os.path.join(DataFile.PACKAGE, 'templates/castero.conf')

    def __init__(self) -> None:
        """
        Note: the config class is a singleton.
        """
        super().__init__(self.PATH, self.DEFAULT_PATH)

        # strictly use default path when testing
        if "pytest" in sys.modules:
            self._path = self._default_path

        self.load()

    def __setitem__(self, key, value):
        pass

def __init__(self, path, default_path) -> None:
        """
        Args:
            path: the path to the data file
            default_path: the path to the default data file
        """
        assert os.path.exists(default_path)

        self.data = collections.OrderedDict()
        self._path = path
        self._default_path = default_path

        # if path doesn't exit, create it based on default_path
        if not os.path.exists(self._path):
            DataFile.ensure_path(self._path)
            copyfile(self._default_path, self._path)

import collections
import json
import os

from castero.datafile import DataFile
from castero.episode import Episode
from castero.feed import Feed


class FeedsError(Exception):
    """An ambiguous error while handling the feeds.
    """


class Feeds(DataFile):
    """The Feeds class.

    Reads and stores information about the user's feeds. Instances of this
    class can generally be treated like dictionaries, accessing a feed with
    feeds_instance[feed_key].

    The feed_key for a feed is either the feed's file path or URL, which each
    feed object is ensured to have exactly one of.
    """
    PATH = os.path.join(DataFile.DATA_DIR, 'feeds')
    DEFAULT_PATH = os.path.join(DataFile.PACKAGE, 'templates/feeds')

    def __init__(self) -> None:
        """Initializes the object.
        """
        super().__init__(self.PATH, self.DEFAULT_PATH)

class ConfigError(Exception):
    """An ambiguous error while handling the configuration.
    """


class ConfigParseError(ConfigError):
    """An error occurred while parsing the config file.
    """


class ConfigDuplicateError(ConfigError):
    """The config file contained a duplicate variable.
    """


class _Config(DataFile):
    """The user's config settings.

    Reads the configuration file. Instances of this class can generally be
    treated like dictionaries, accessing a variable with config_instance[key].

    Modifying config variables inside the application is not supported; config
    changes must be made to the config file itself.
    """
    PATH = os.path.join(DataFile.CONFIG_DIR, 'castero.conf')
    DEFAULT_PATH = os.path.join(DataFile.PACKAGE, 'templates/castero.conf')

    def __init__(self) -> None:
        """
        Note: the config class is a singleton.
        """
        super().__init__(self.PATH, self.DEFAULT_PATH)

from castero.queue import Queue


class Database():
    """The user's database.

    This class provides an API for storing and retrieving data from an sqlite
    database file.

    The database replaces the Feeds class which stored feed/episode data in a
    JSON file. We automatically migrate users from that format to the database:
    see _create_from_old_feeds().

    For schema details, see $PACKAGE/templates/migrations.
    """
    PATH = os.path.join(DataFile.DATA_DIR, 'castero.db')
    OLD_PATH = os.path.join(DataFile.DATA_DIR, 'feeds')
    MIGRATIONS_DIR = os.path.join(DataFile.PACKAGE, 'templates/migrations')

    SQL_EPISODES_BY_ID = "select feed_key, id, title, description, link, pubdate, copyright, enclosure, played from episode where id=?"
    SQL_EPISODES_BY_FEED = "select id, title, description, link, pubdate, copyright, enclosure, played from episode where feed_key=?"
    SQL_EPISODE_REPLACE = "replace into episode (id, title, feed_key, description, link, pubdate, copyright, enclosure, played)\nvalues (?,?,?,?,?,?,?,?,?)"
    SQL_EPISODE_REPLACE_NOID = "replace into episode (title, feed_key, description, link, pubdate, copyright, enclosure, played)\nvalues (?,?,?,?,?,?,?,?)"
    SQL_FEEDS_ALL = "select key, title, description, link, last_build_date, copyright from feed"
    SQL_FEED_BY_KEY = "select key, title, description, link, last_build_date, copyright from feed where key=?"
    SQL_FEED_REPLACE = "replace into feed (key, title, description, link, last_build_date, copyright)\nvalues (?,?,?,?,?,?)"
    SQL_FEED_DELETE = "delete from feed where key=?"
    SQL_QUEUE_ALL = "select id, ep_id from queue"
    SQL_QUEUE_REPLACE = "replace into queue (id, ep_id)\nvalues (?,?)"
    SQL_QUEUE_DELETE = "delete from queue"

    def __init__(self):

def _feed_directory(self) -> str:
        """Gets the path to the downloaded episode's feed directory.

        This method does not ensure whether the directory exists -- it simply
        acts as a single definition of where it _should_ be.

        Returns:
            str: a path to the feed directory
        """
        feed_dirname = helpers.sanitize_path(str(self._feed))
        if Config is None or Config["custom_download_dir"] == "":
            path = DataFile.DEFAULT_DOWNLOADED_DIR
        else:
            path = \
                os.path.expandvars(
                    os.path.expanduser(
                        Config["custom_download_dir"]))
            if not path.startswith('/'):
                path = "/%s" % path
        return os.path.join(path, feed_dirname)