[Python-Dev] xrange identity crisis

[Guido van Rossum]

[Raymond Hettinger]
> Xrange was given its own tp_iter slot and now runs as fast a range.
> In single pass timings, it runs faster.  In multiple passes, range
> is still quicker because it only has to create the PyNumbers once.
> 
> Being immutable, xrange had the advantage that it could serve as its
> own iterator and did not require the extra code needed for list
> iterators and dict iterators.

Did you write the pach that Martin checked in?

It's broken.

>>> a = iter(xrange(10))
>>> for i in a:
        print i    
        if i == 4: print '*', a.next()
    
0
1
2
3
4
* 0
5
6
7
8
9
>>>

Compare to:

>>> a = iter(range(10))
>>> for i in a:
        print i
        if i == 4: print '*', a.next()
    
0
1
2
3
4
* 5
6
7
8
9
>>> 

--Guido van Rossum (home page: http://www.python.org/~guido/)