code: def _open_sqlite(db_file):
      
      db_file = os.path.expanduser(db_file)
      try:
          with open(db_file):
              # test that the file can be accessed
              pass
          return sqlite3.connect(db_file, detect_types=sqlite3.PARSE_DECLTYPES)
      except (IOError, sqlite3.Error) as err:
          raise Dump2PolarionException("{}".format(err))
docs: Opens database connection.