On 02:50 am, lie.1...@gmail.com wrote:
On 12/14/2009 9:45 AM, exar...@twistedmatrix.com wrote:
On 08:18 pm, st...@remove-this-cybersource.com.au wrote:
On Sun, 13 Dec 2009 14:35:21 +0000, exarkun wrote:
StopIteration is intended to be used only within the .__next__
method of
iterators. The devs know that other 'off-label' use results in the
inconsistency you noted, but their and my view is 'don't do that'.
Which is unfortunate, because it's not that hard to get
StopIteration
without explicitly raising it yourself and this behavior makes it
difficult to debug such situations.
I can't think of any way to get StopIteration without explicitly
raising
it yourself. It's not like built-ins or common data structures
routinely
raise StopIteration. I don't think I've *ever* seen a StopIteration
that
I didn't raise myself.
Call next on an iterator. For example: iter(()).next()
.next() is not meant to be called directly
Doesn't matter. Sometimes it makes sense to call it directly. And I
was just giving an example of a way to get StopIteration raised without
doing it yourself - which is what Steve said he couldn't think of.
I'm surprised to hear you say that the magical faerie land behavior
isn't desirable either, though. I'd love a tool that did what I
wanted,
not what I asked. The only serious argument against this, I think, is
that it is beyond our current ability to create (and so anyone
claiming
to be able to do it is probably mistaken).
In your world, this is what happens:
>>> list = [a, b, c]
>>> # print list
>>> print list
["a", "b", "c"]
>>> # make a copy of list
>>> alist = list(llst) # oops a mistype
>>> alist = alist - "]" + ", "d"]"
>>> print alist
["a", "b", "c", "d"]
>>> alist[:6] + "i", + alist[6:]
>>> print alist
["a", "i", "b", "c", "d"]
>>> print alist
>>> # hearing the sound of my deskjet printer...
>>> C:\fikle.text.write(alist)
>>> print open("C:\file.txt").read()
<h1>a</h1>
<ul>
<li>i</li>
<li>b</li>
<li>c d</li>
>>> # great, exactly what I needed
I don't understand the point of this code listing, sorry. I suspect you
didn't completely understand the magical faerie land I was describing -
where all your programs would work, no matter what mistakes you made
while writing them.
Jean-Paul
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