On Fri, 08 Oct 2010 12:10:50 +0000, kj wrote: > In <4cae667c$0$29993$c3e8da3$54964...@news.astraweb.com> Steven D'Aprano > <st...@remove-this-cybersource.com.au> writes: > >>On Fri, 08 Oct 2010 00:23:30 +0000, kj wrote: > >>Because it's always better to use a well-written, fast, efficient, >>correct, well-tested wheel than to invent your own slow, incorrect wheel >>:) > > IOW, "don't you worry your little head about why."
Shame on you for deleting the context of my answer. You said: "I imagine that frozenset is better than sorted(tuple(...)) here, but it's not obvious to me why." Because frozenset already works. Because somebody else has done the work, and debugged it, and tested it, and profiled it, and optimized it, and ensured that it is correct and fast. That saves you a lot of effort, and frees you from having to duplicate the same functionality, and debugging it, testing it, profiling it, and optimizing it. Every line of code that you can avoid writing is a win. If you're a carpenter, it is better to buy a hammer than it is to go out and dig up your own iron ore, smelt the metal, and forge it into a hammer: unless you're in the business of making hammers, you've got better things to do with your time. And if you're a programmer, you've got better things to do than write a slower, buggier version of code that already exists. If you want to know *what* the frozenset does that is better, then go read the source code. For all I know you might discover that it does the same thing as your code. It's *still* better to use frozenset, simply because it already exists. Unless you profile your code and discover that frozenset is too slow and you can do better, there is no reason not to use it, and many reasons to use it. This has nothing to do with "your little head", but about code reuse. Almost the entire history of programming, from the invention of sub- routines to the open source movement, is about code reuse. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
