[Python-Dev] Iterable String Redux (aka String ABC) (original) (raw)

Georg Brandl g.brandl at gmx.net
Tue May 27 23:31:06 CEST 2008

Antoine Pitrou schrieb:

Georg Brandl <g.brandl gmx.net> writes:

I'd argue that "find" is more primitive than "split" -- split is intuitively implemented using find and slicing, but implementing find using split and len is unintuitive. (Of course, "index" can be used instead of "find".) I meant semantically primitive. I think the difference between a String and a plain Sequence is that, in a String, the existence and relative position of substrings has a meaning. This is true for character strings but it can also be true for other kinds of strings (think genome strings, they are usually represented using ASCII letters but it's out of convenience - they could be made of opaque objects instead). That's why, in string classes, you have methods like split() to deal with the processing of substrings - which you do not have on lists, not that's it more difficult to implement or algorithmically less efficient, but because it makes no point. Well I hope it makes at least a bit of sense :-)

It does, but I don't see how it contradicts my proposition. find() takes a substring as well.

Georg

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