Arthur: > > Are you a CS type? If so, speak directly. I'm a CS type (BS in CS, MS in CSEE). Kirby's right, it's generally considered "better" to return a new primitive type rather than mutate it in place. Many programming languages impose "striction functionality" which means you have no (or nearly no) mutable state at all, just returning new values. This can avoid many, many types of problems in programming, but isn't as friendly in some cases.
For "better" in the first sentence above you can insert any of: faster, more stable, less error-prone, and frequently more readable. Arthur: > > If not, why do you feel compelled to speak on their behalf. Kirby: > I'm volunteering this information. And therein I think we have the nub of the frequent Arthur/Kirby semi-argument. My impression is that Kirby often offers suggestions and information, and Arthur interprets this as telling him what to do and pushes back. No idea what to do about this, just pointing it out. Arthur: > > My complex number is an old fashioned object. For my purposes - destroying > > it and > > recreating another every time a value changes is wasteful, (and cruel ;)) Wasteful how? By implementing your own complex type and ignoring the built-in one you are wasting memory, speed, and (arguably) your time. The bytes that are thrown away when an existing complex object is reclaimed are treated humanely and given a decent recycling to emerge as new objects. Where is the waste? Kirby: > That's > how primitive numbers behave too. -2 .__invert__() returns 3, doesn't > alter -2 in any way. I hadn't noticed the __invert__ method before so I tested this: -2.__invert__() gave a SyntaxError (-2).__invert__() gave 1 (2).__invert__() gave -3 Just to be pedantic about it. %-) > It all depends on your goals. If your goal is a working PyGeo with > code your well understand, then the mutable complex number may be no > hindrance at all. If your goal is to get your source code studied in > CS departments, as exemplary of how to go about coding such a VPython > app, that'd be a different challenge. That about sums it up. You can make up you're own types to your hearts content: mutable ints and floats if you want. It can be a good learning experience, as long as you're not trying to to pass it off as a best practice. --Dethe _______________________________________________ Edu-sig mailing list Edu-sig@python.org http://mail.python.org/mailman/listinfo/edu-sig
