Re: dict!ident as equivalent of dict[ident]
Edward Elliott wrote: With this suggestion, mapping!identifier becomes fully equivalent to mapping[identifier] Penny-wise, pound-foolish. Saves 3 character strokes at the cost of a new special-purpose operator which only works in limited circumstances. To avoid parsing ambiguity, identifier can only contain (as the name implies) alphanumerics and _. So your ! is limited not only to dicts but to certain keys in certain dicts. More complicated than it's worth. Yes, it is limited use-case, but IMHO important one. The benefits are: 1. Code looks more neat, because IDE will highlight it as identifier, and not as string 2. Limited form of code completion (as in PythonWin) becomes possible 3. A bit easier to type, and to read Anyway, I don't intent strongly on this, I just like to see common attitude So your ! is limited not only to dicts Not only to dict, but to any class with __getitem__ or __setitem__ methods -- Best regards, Alexander mailto:[EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: dict!ident as equivalent of dict[ident]
In article [EMAIL PROTECTED], Alexander Kozlovsky [EMAIL PROTECTED] wrote: Hello all! I have small silly syntax suggestion () In many cases, keys in dictionary-like objects are strings, and moreover - valid Python identifiers. Something like: foo[bar][baz].x = y How about small syntactic sugar: foo!bar!baz.x = y Ugh. Syntactic sugar like that leads to language obesity. Anyway, you can already do what you want with just a little bit of work. Define a class (perhaps a subclass of dict, if you like) with a __getattr__ method. Then you can just do foo.bar.baz.x = y with no changes needed to the language. -- http://mail.python.org/mailman/listinfo/python-list
Re: dict!ident as equivalent of dict[ident]
On Sun, 21 May 2006 16:19:29 +0400, Alexander Kozlovsky [EMAIL PROTECTED] wrote: How about small syntactic sugar: foo!bar!baz.x = y With this suggestion, mapping!identifier becomes fully equivalent to mapping[identifier] Take a look at the Bunch recipe in the Python Cookbook: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52308 Regards, Dan -- Dan Sommers http://www.tombstonezero.net/dan/ I wish people would die in alphabetical order. -- My wife, the genealogist -- http://mail.python.org/mailman/listinfo/python-list
Re: dict!ident as equivalent of dict[ident]
Roy Smith wrote: Define a class (perhaps a subclass of dict, if you like) with a __getattr__ method. Then you can just do foo.bar.baz.x = y with no changes needed to the language. I think, your solution is very error-prone. If such enhanced dictionary contains keys key, what is meaning of d.keys? Is it bound method or dictionary item? After you introduce such dictionary, you cannot add any new method for it, because it may destroy user code, if acciddent name clashing take place. Consider SQLTable class, which have name attribute, and bunch of dynamically created named columns. With __getattr__ method you can use SQLTable.column_1 syntax for column access, but what if same column have name name? It may be very psychologically inconvenient for user of such class to use same foo.bar syntax for two different purposes. In most real cases it is important to distinguish between two different namespaces - members namespace with methods properties etc., and items namespace with truly dynamic content. In todays Python such distinction accomplished with two different methods - __getattr(ibute)__ and __getitem__. It is not possible to successfully use only __getattr__ to serve two different purposes. Hense I suggest use __getitem__ for its direct purpose, and only add some syntactic sugar for it Dan Sommers wrote: Take a look at the Bunch recipe in the Python Cookbook: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52308 This recipe is what is stated in its name - collector of a bunch of named stuff. It is not suitable for elaborate classes with many methods (such as SQLTable), for above mentioned reason - name cluttering between methods, properties and dynamic content. -- Best regards, Alexander mailto:[EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: dict!ident as equivalent of dict[ident]
Alexander Kozlovsky wrote: With this suggestion, mapping!identifier becomes fully equivalent to mapping[identifier] Penny-wise, pound-foolish. Saves 3 character strokes at the cost of a new special-purpose operator which only works in limited circumstances. To avoid parsing ambiguity, identifier can only contain (as the name implies) alphanumerics and _. So your ! is limited not only to dicts but to certain keys in certain dicts. More complicated than it's worth. -- Edward Elliott UC Berkeley School of Law (Boalt Hall) complangpython at eddeye dot net -- http://mail.python.org/mailman/listinfo/python-list
