What is the purposeof replacing "<unknown id>" with "id"?

[jan-glx]

https://github.com/BjornFJohansson/pydna/blob/75fa7e2c783eabfa32f580d7c0ea2620f907390b/src/pydna/seqrecord.py#L630

[BjornFJohansson]

Hi @jan-glx
I think the is so very ugly...

[jan-glx]

the "<unkown id>"? Shouldn't it rather be None with the printing function taking care of displaying that in a sensible way. Might break some code though. What would you think about answer.name = "-".join((name for name in (self.name, other.name) if name is not None))?