Oh, I didn't even know about `format_map`! Or `__format__` for that matter. This makes everything much easier. For my purposes, I don't even need to use `__format__` since I am not using format strings. In a show of appreciation, here is a URL to a GIF of James Corden bowing: https://media.giphy.com/media/l2R0eYcNq9rJUsVAA/giphy.gif ``` class Options(UserDict): def __getitem__(self, key): if key in self: return super().__getitem__(key) key, *default = key.split('?') if key in self: return super().__getitem__(key) return ''.join(default) options = {'baud': 19200} result = 'BAUD: {baud?9600}'.format_map(Options(options)) print(result) options = {} result = 'BAUD: {baud?9600}'.format_map(Options(options)) print(result) ```