def __getitem__(self, key):
        """Index into file's lines and get a parsed reference back."""
        if key not in self:
            raise KeyError('{}[{!r}]'.format(self.__class__.__name__, key))
        line = self.__lines[int(key)]
        return self.__parse(line)
Index into file's lines and get a parsed reference back.
recipes/Python/577049_Bible_Verse_Quiz__librarypy/recipe-577049.py