How to use the buku.BukuDb.get_default_dbdir function in buku

# desktop generic
        os.environ.pop('XDG_DATA_HOME')
        self.assertEqual(dbdir_local_expected, BukuDb.get_default_dbdir())

        # no desktop

        # -- home is defined differently on various platforms.
        # -- keep a copy and set it back once done
        originals = {}
        for env_var in ['HOME', 'HOMEPATH', 'HOMEDIR']:
            try:
                originals[env_var] = os.environ.pop(env_var)
            except KeyError:
                pass
        self.assertEqual(dbdir_relative_expected, BukuDb.get_default_dbdir())
        for key, value in list(originals.items()):
            os.environ[key] = value

def test_get_default_dbdir(self):
        dbdir_expected = TEST_TEMP_DBDIR_PATH
        dbdir_local_expected = os.path.join(os.path.expanduser('~'), '.local', 'share', 'buku')
        dbdir_relative_expected = os.path.abspath('.')

        # desktop linux
        self.assertEqual(dbdir_expected, BukuDb.get_default_dbdir())

        # desktop generic
        os.environ.pop('XDG_DATA_HOME')
        self.assertEqual(dbdir_local_expected, BukuDb.get_default_dbdir())

        # no desktop

        # -- home is defined differently on various platforms.
        # -- keep a copy and set it back once done
        originals = {}
        for env_var in ['HOME', 'HOMEPATH', 'HOMEDIR']:
            try:
                originals[env_var] = os.environ.pop(env_var)
            except KeyError:
                pass
        self.assertEqual(dbdir_relative_expected, BukuDb.get_default_dbdir())
        for key, value in list(originals.items()):
            os.environ[key] = value

Create DB file and/or bookmarks table if they don't exist.
        Alert on encryption options on first execution.

        Parameters
        ----------
        dbfile : str, optional
            Custom database file path (including filename)

        Returns
        -------
        tuple
            (connection, cursor)
        """

        if not dbfile:
            dbpath = BukuDb.get_default_dbdir()
            filename = 'bookmarks.db'
            dbfile = os.path.join(dbpath, filename)
        else:
            dbfile = os.path.abspath(dbfile)
            dbpath, filename = os.path.split(dbfile)

        try:
            if not os.path.exists(dbpath):
                os.makedirs(dbpath)
        except Exception as e:
            logerr(e)
            os._exit(1)

        db_exists = os.path.exists(dbfile)
        enc_exists = os.path.exists(dbfile + '.enc')

try:
            from cryptography.hazmat.backends import default_backend
            from cryptography.hazmat.primitives.ciphers import (Cipher, modes, algorithms)
            from getpass import getpass
            from hashlib import sha256
            import struct
        except ImportError:
            logerr('cryptography lib(s) missing')
            sys.exit(1)

        if iterations < 1:
            logerr('Decryption failed')
            sys.exit(1)

        if not dbfile:
            dbfile = os.path.join(BukuDb.get_default_dbdir(), 'bookmarks.db')
        else:
            dbfile = os.path.abspath(dbfile)
            dbpath, filename = os.path.split(dbfile)

        encfile = dbfile + '.enc'

        enc_exists = os.path.exists(encfile)
        db_exists = os.path.exists(dbfile)

        if enc_exists and not db_exists:
            pass
        elif not enc_exists:
            logerr('%s missing', encfile)
            sys.exit(1)
        else:
            # db_exists and enc_exists

try:
            from cryptography.hazmat.backends import default_backend
            from cryptography.hazmat.primitives.ciphers import (Cipher, modes, algorithms)
            from getpass import getpass
            from hashlib import sha256
            import struct
        except ImportError:
            logerr('cryptography lib(s) missing')
            sys.exit(1)

        if iterations < 1:
            logerr('Iterations must be >= 1')
            sys.exit(1)

        if not dbfile:
            dbfile = os.path.join(BukuDb.get_default_dbdir(), 'bookmarks.db')
        encfile = dbfile + '.enc'

        db_exists = os.path.exists(dbfile)
        enc_exists = os.path.exists(encfile)

        if db_exists and not enc_exists:
            pass
        elif not db_exists:
            logerr('%s missing. Already encrypted?', dbfile)
            sys.exit(1)
        else:
            # db_exists and enc_exists
            logerr('Both encrypted and flat DB files exist!')
            sys.exit(1)

        password = getpass()