Steven D'Aprano wrote: > There is no significant speed difference between immutable and mutable > sets, at least for queries. Regardless of whether it is successful or > unsuccessful, mutable or immutable, it takes about 0.0000025 second to do > each test of item in set. Why would you need to optimize that? > > If you tell us what you are trying to do, and under what circumstances it > is too slow, we'll see if we can suggest some ways to optimize it. > > But if you are just trying to optimize for the sake of optimization, > that's a terrible idea. Get your program working first. Then when it > works, measure how fast it runs. If, and ONLY if, it is too slow, > identify the parts of the program that make it too slow. That means > profiling and timing. Then optimize those parts, and nothing else. > > Otherwise, you will be like the car designer trying to speed up his sports > cars by making the seatbelts aerodynamic.
No need for the 'premature optimization is the root of all evil' speech. I'm not trying to optimize anything - just enquiring about the nature of frozenset. If typing 'frozenset' over 'set' gave me a saving in time or memory (even if tiny) I would favour immutable sets, where appropriate. Thanks for the info. Will -- http://www.willmcgugan.com "".join({'*':'@','^':'.'}.get(c,0) or chr(97+(ord(c)-84)%26) for c in "jvyy*jvyyzpthtna^pbz") -- http://mail.python.org/mailman/listinfo/python-list