"Guido van Rossum" wrote in message news:ca471dc20705071703p54a9afc3yfe9693c5fe6e2f23@mail.gmail.com... | But why bother? The 2to3 converter can do this for you. | | In a sense using range() is more likely to produce broken results in | 3.0: if your code depends on the fact that range() returns a list, it | is broken in 3.0, and 2to3 cannot help you here. But if you use | list(xrange()) today, the converter will turn this into list(range()) | in 3.0 and that will continue to work correctly. Just curious why 2to3 would not replace range() with list(range())? tjr

Just curious why 2to3 would not replace range() with list(range())?

In most usages of range(), using the 3.0 range() will work just as well, and be more efficient. If I wanted to write code that works in both versions (which I understand is not the 2to3 objective), then I would use range(). If I worry about creating a list in 2.x, I would write try: xrange except NameError: xrange=range at the top of the file. Regards, Martin

On 5/8/07, Armin Rigo wrote:

On Tue, May 08, 2007 at 09:14:02AM +1000, Anthony Baxter wrote:

...

I'd like to suggest that we remove all (or nearly all) uses of xrange from the stdlib. A quick scan shows that most of the usage of it is unnecessary. With it going away in 3.0, and it being informally deprecated anyway, it seems like a good thing to go away where possible.

The first step is to focus the question on the places where replacing xrange() with range() can really make no difference at all, as far as we can see. This is not the case of "nearly all" the uses of xrange() from the stdlib - but it's still the case of a number of them:

''.join(chr(x) for x in xrange(256)) # at global module level

or:

for i in xrange(self.firstweekday, self.firstweekday + 7):

I personally think that replacing these with range() is a clean-up, but I also know that not everybody agrees to that. So: should we, or should we not, replace xrange() with range() as a matter of clean-up when the difference between the two is really completely irrelevant?

I'm all for that -- personally, I wouldn't have written xrange() in the first place in such cases! -- --Guido van Rossum (home page: http://www.python.org/~guido/)

* James Y Knight [2007-05-08 11:18:44]:

On May 8, 2007, at 8:49 AM, Armin Rigo wrote:

...

On Tue, May 08, 2007 at 09:14:02AM +1000, Anthony Baxter wrote:

...

I'd like to suggest that we remove all (or nearly all) uses of xrange from the stdlib. A quick scan shows that most of the usage of it is unnecessary. With it going away in 3.0, and it being informally deprecated anyway, it seems like a good thing to go away where possible.

I personally think that replacing these with range() is a clean-up, but I also know that not everybody agrees to that. So: should we, or should we not, replace xrange() with range() as a matter of clean-up when the difference between the two is really completely irrelevant?

But doesn't doing this now this make the conversion to Py3 *harder*? If 2to3 is going to rewrite xrange() as range(), and range() to list (range()), then moving towards xrange where possible would actually be preferable, wouldn't it? Or is there no plan to run 2to3 on the stdlib?

Looking at xrange() and range() definitions and from this discussion, it seems to me that xrange() to be preferable over range(). Its common that most of the code have range() because its simple use in iteration, but if same functionality is provided with xrange as an object. And doing :s/xrange/range/g would make sense also. ( Am I right in understanding this?) Why range or xrange and why not xrange or range? Or is this discussion about why having two functions with similar (or rather same) functionality, and lets move to one and in which case either of them is fine. -- O.R.Senthil Kumaran