[Python-3000] Default dict iterator should have been iteritems()

[Gregory P. Smith]

On 9/4/07, "Martin v. Löwis" <martin at v.loewis.de> wrote:
>
> > (assuming d[x] is  O(log n))
>
> In Python, d[x] is typically considered to be O(1) (unlike in C++,
> where it is O(log n)). Of course, with Python using a hashtable,
> performance may decrease in the presence of collisions. In the
> normal case, dict((x, d[x]) for x in d) will be O(n) in Python.


And if the speed of d[x] were ever an issue that shows up on python
performance profiles when used in a loop like that it would be pretty easy
to optimize the common case internally by having the key iteration retain an
optional (weak?) reference in the dict object to the most recently looked up
key+value for a short circuit quickly returning its value.  I do not expect
that to ever to matter as code can just loop using the appropriate iterator
instead.

-gps
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