Re: non-copy slices
On Thu, Nov 19, 2009 at 2:44 PM, Ethan Furman et...@stoneleaf.us wrote: Please don't top post. :) So shallow copy == new label created for existing object. So is your desired behavior to write back to the original list if your sub-list is modified? In other words, you are creating a window onto an existing list? If not, what would happen when a sublist element was modified (or deleted, or appended, or ...)? ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list Yes a window / view on the existing list describes it best. So every modification you make in this view is actually modifying the original list accordingly. Blist that was suggested in a previous email in the thread seems lightweight but it does create a new list when a modification is made. In any case, I've already implemented the object myself and I can post it if you care to have a look, but I was just wondering if there was already something in the standard library. Themis -- http://mail.python.org/mailman/listinfo/python-list
Re: non-copy slices
Sth else that I noticed as I started using islice. The name is somewhat misleading. Having the slice part in the name I would expect it to imitate the functionality of normal slices. Random access, sub-slicing etc. However, it is only iteratable. Any particular reasons for that? My guess is that it's inside the itertools so it's meant only for iteration and not random access. However, as I told before the name implies the same functionality while the only thing they share is iteration. It's nothing in the library that completely imitates the slice without the copies, right? Cheers, Themis On Wed, Nov 18, 2009 at 6:49 PM, Terry Reedy tjre...@udel.edu wrote: tbour...@doc.ic.ac.uk wrote: Hi, I was looking for a facility similar to slices in python library that would avoid the implicit creation of a new list and copy of elements that is the default behaviour. Instead I'd rather have a lazy iteratable object on the original sequence. Well, in the end I wrote it myself but I was wondering if I missed sth in the library If I didn't is there a particular reason there isn't sth like that? I find it hard to believe that all slice needs have strictly copy semantics. It is a strict *shallow* copy. There is no copying of contents. That aside, you are right, hence itertools.islice as already mentioned. In the design of 3.0, I believe the idea was raised of making slices iterables in 3.0, just as was done for map, filter, and range. However, it would have been highly disruptive, and not save much space. Map and range create an unbounded number of new objects, rather than just a sequence of references to existing objects (or bytes or words for bytes and str slices). There is also the problem of virtual slices preventing garbage collection of the source sequence when it is not otherwise needed. Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: method decorators and more on decorators
On Mon, Jul 28, 2008 at 11:12 AM, Gabriel Genellina [EMAIL PROTECTED]wrote: En Sun, 27 Jul 2008 15:26:39 -0300, Themistoklis Bourdenas [EMAIL PROTECTED] escribió: On a related note, as the actual instance method of myclass is not foo but decorate(foo), why are they called method decorators? This does not decorate methods, they decorate functions and eventually the decorated functions become methods. The name method decorator sounds a bit misleading to me. Where have you found it? I've always seen the expression function decorator or just decorator, not method decorator. well a few occurrences of it can be found in PEP 318 So returning to my original question is there any way I can get the class inside decorate()? I guess there is not, but just asking to make sure. the class inside decorate? What do you mean? The type of the x instance in an x.foo() call? That should be determined inside the wrapped function -when it is actually called-. Yes, what I was hoping is that it might be possible to get the name of the class the function is eventually is going to be bound to, but I guess that's not very likely to be possible. I wanted the name well before the function is called, actually even before an instance of the class is created. Anyway, I 've solved my problem with other means. Just out curiosity though, has there been any talk about actual method decorators? I guess you can work around them with the introduction of class decorators or even now with meta-classes, but you have to wrap methods manually with no syntactic sugar. Cheers, Themis -- http://mail.python.org/mailman/listinfo/python-list
Re: Module clarification
I would recommend dive into python. Its available free online (just google it) and it tries to teach you python, not programming which unfortunately many books try to do. It assumes that you already have some experience with C++ or Java and contradicts python syntax/semantics to those languages. Very useful and fast if you already know how to program. Cheers, Themis On Mon, Jul 28, 2008 at 6:57 PM, Marcus.CM [EMAIL PROTECTED]wrote: Hi Hussein, Basically a module is a FILE and is considered as a singleton model. Yes ur wow.py assumption is correct. I recommend getting Mark Lutz Learning Python book to get you started. Marcus.CM Hussein B wrote: Hi. I'm a Java guy and I'm playing around Python these days... In Java, we organize our classes into packages and then jarring the packages into JAR files. What are modules in Python? What is the equivalent of modules in Java? Please correct me if I'm wrong: I saved my Python code under the file Wow.py Wow.py is now a module and I can use it in other Python code: import Wow Thanks. -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
