def __contains__(self, item):
        """Verify if the given string can refer to a line in the file."""
        try:
            index = int(item)
        except ValueError:
            return False
        else:
            return 0 <= index < len(self.__lines)
Verify if the given string can refer to a line in the file.
recipes/Python/577049_Bible_Verse_Quiz__librarypy/recipe-577049.py