Fernando Perez <[EMAIL PROTECTED]> wrote:
> > Alan Green <[EMAIL PROTECTED]> wrote:
> >> Steven Bethard is proposing a new collection class named Bunch. I had
> >> a few suggestions which I attached as comments to the patch - but what
> >> is really required is a bit more work on the draft PEP, and then
> >> discussion on the python-dev mailing list.
>
> But one thing which I really find necessary from a useful 'Bunch' class, is
> the ability to access attributes via foo[name] (which requires implementing
> __getitem__). Named access is convenient when you _know_ the name you need
> (foo.attr). However, if the name of the attribute is held in a variable, IMHO
> foo[name] beats getattr(foo,name) in clarity and feels much more 'pythonic'.
My feeling about this is that if the name of the attribute is held in
a variable, you should be using a dict, not a Bunch/Struct. If you
have a Bunch/Struct and decide you want a dict instead, you can just
use vars:
py> b = Bunch(a=1, b=2, c=3)
py> vars(b)
{'a': 1, 'c': 3, 'b': 2}
> Another useful feature of this Struct class is the 'merge' method.
[snip]
> my values() method allows an optional keys argument, which I also
> find very useful.
Both of these features sound useful, but I don't see that they're
particularly more useful in the case of a Bunch/Struct than they are
for dict. If dict gets such methods, then I'd be happy to add them to
Bunch/Struct, but for consistency's sake, I think at the moment I'd
prefer that people who want this functionality subclass Bunch/Struct
and add the methods themselves.
> I think the current pre-PEP version is a bit too limited to be generally
> useful in complex, real-world situtations. It would be a good starting point
> to subclass for more demanding situations, but IMHO it would be worth
> considering a more powerful default class.
I'm probably not willing to budge much on adding dict-style methods --
if you want a dict, use a dict. But if people think they're
necessary, there are a few methods from Struct that I wouldn't be too
upset if I had to add, e.g. clear, copy, etc. But I'm going to need
more feedback before I make any changes like this.
Steve
--
You can wordify anything if you just verb it.
--- Bucky Katt, Get Fuzzy
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