On Thu, Apr 1, 2010 at 3:34 PM, kj <no.em...@please.post> wrote: > When coding C I have often found static local variables useful for > doing once-only run-time initializations. <snip> > Another approach would be to stuff the static values in the function's > __dict__. This is less satisfactory than the closure approach > because the "pseudo-static" variable is accessible from outside > the function, but the code is arguably a little more straightforward, > and one does not end up with the now useless one-time closure-generating > function kicking around. Here's another version of the function > above: > >>>> def spam(): > ... d = spam.__dict__ > ... if not 's' in spam.__dict__: > ... spam.s = 1 > ... print spam.s > ... spam.s += 1 > ... >>>> spam() > 1 >>>> spam() > 2 >>>> spam() > 3 > > Besides the external accessibility issue, I don't like explictly > coding the name of the function within the function. Is there any > way to have the function access its own __dict__ without having to > explicitly code its name in its body? E.g., is there some generic > special variable that, within a function, refers to the function > object itself?
Nope. It's been proposed in that past (http://www.python.org/dev/peps/pep-3130/), but that proposal was rejected. > I'm sure that there are many other ways to skin this cat, especially > if one starts definining fancy callable classes and whatnot. But > is there a better *simple* way to achieve C-style static locals in > Python that does not require a lot of extra machinery? You can abuse the default argument value mechanism: def spam(s_cell=[1]): s = s_cell[0] print s s_cell[0] += 1 It's a bit less ugly when the value itself is mutable, which isn't the case here with the integer. Personally, I hate such abuse with a passion; I think a global variable is clearest. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
