In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] wrote: > >1. The fact that one function calls the other doesn't mean they're > >"logically nested".< > > In this situation they were logically nested, because the scramble_word > is a function needed by another one only, in Java the scramble_word > becomes a (private) method of a text scrambling class; this means it is > nested and hided inside a class. Pascal languages were pre-OOP and they > used nested function for similar purposes, that it to hide and > structure functions inside other ones, that in OO languages like Java, > ObjectPascal, Python, etc. you usually do with classes.
In Python one usually doesn't try to hide things. [ ... ] > >4. I don't buy the namespace pollution argument, we have modules after all. > > I presume Guido agrees that function nesting is another way to avoid > namespace pollution :-) I dare you to find out. I'm fairly sure of the answer. > There are many ways to do the same thing, to > avoid pollution in one module. Nesting functions is not one of them. Factoring a bit of functionality into a helper function, giving that function a name and sticking it into a module can _hardly_ be called "pollution". That's what modules are *for*. [ ... ] > >To me, nested functions (in Python) are *only* helpful when using closures. > >If you're not using the enclosing scope, you're just obfuscating things.< > > Note that until recent time, Python nested scopes were managed quite > differently (in a bad way), Yup. > and yet, they regarded the function nesting > useful enough to be kept anyway. Nested functions are supported because you _need_ them if you want to work with closures. Not because it's a good way to structure code in the *absence* of closures. > I don't agree with you, but every programmer is diffent, because their > story is different. If you have learnt to program with Java/C then you > probably don't like nested functions. If you started with a Pascal-like > language then probably you like that nesting more. If you start with a > Scheme/Lisp background you progrably write Python programs like the > good Norvig: > http://aima.cs.berkeley.edu/python/utils.py That's pretty good code. Well documented, clearly written, uses some functional idioms in a sensible way. And no, it doesn't use gratuitous nested functions. > Maybe other people here can say what they think about this topic, it's > just a relaxed discussion. Sure, it's just that I feel strongly that your advice is not a good one (*especially* for beginners). So I repeat: using nested functions are NOT a good way to factor your code. (I don't need to add "in Python" there, do I?) Just -- http://mail.python.org/mailman/listinfo/python-list
