On Wed, 18 Apr 2007 01:45:10 -0700, Paul McGuire wrote:
For the record, this is what I actually wanted: a four-line self-sorting
dictionary:
class SortedDict(dict):
def __iter__(self):
for key in sorted(self.keys()):
yield key
[snip]
Very neat. Why not this?
On Wed, 18 Apr 2007 19:45:50 -0700, Alex Martelli wrote:
7stud [EMAIL PROTECTED] wrote:
...
Can you explain some of the details of why this code fails:
...
def next(self):
for word in Norwegian Blue's have beautiful
plumage!.split():
yield word
Sure,
7stud wrote:
Hi,
Thanks for the responses.
7stud [EMAIL PROTECTED] wrote:
Can you explain some of the details of why this code fails:
---
class Parrot(object):
def __iter__(self):
return self
def __init__(self):
self.next = self.next().next
def
7stud [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
| On Apr 18, 8:38 pm, Terry Reedy [EMAIL PROTECTED] wrote:
|
| One very good way to get an iterator from an iterable is for .__iter__
to
| be a generator function.
|
| Ahhh. That eliminates having to deal with next().next
On Apr 19, 5:37 am, Steve Holden [EMAIL PROTECTED] wrote:
It's nothing to do with the name lookup. Alex mentioned that to remind
us that the magic double-under names are looked up on the type rather
than the instance...
P.next()
vs.
type(P).next()
Where is the double-under name?
--
On Apr 19, 3:12 pm, 7stud [EMAIL PROTECTED] wrote:
On Apr 19, 5:37 am, Steve Holden [EMAIL PROTECTED] wrote:
It's nothing to do with the name lookup. Alex mentioned that to remind
us that the magic double-under names are looked up on the type rather
than the instance...
P.next()
vs.
7stud wrote:
On Apr 19, 5:37 am, Steve Holden [EMAIL PROTECTED] wrote:
It's nothing to do with the name lookup. Alex mentioned that to remind
us that the magic double-under names are looked up on the type rather
than the instance...
P.next()
vs.
type(P).next()
Where is the
7stud [EMAIL PROTECTED] wrote:
...
repeatedly calls[type(_t).next(t)]
As far as I can tell, if the call was actually _t.next(), the code I
asked about would work. However, the name look up for 'next' when you
All of your following lamentations are predicated on this assumption, it
Steven D'Aprano [EMAIL PROTECTED] wrote:
Calling a generator, such as this next method, returns an iterator
object; calling it repeatedly returns many such iterator objects, and
never raises StopIteration, thus obviously producing an unending loop.
Thank you for that answer Alex, even
On Thu, 19 Apr 2007 20:00:31 -0700, Alex Martelli wrote:
class sane(object):
def __init__(self, sentence='four scores and twenty years ago'):
def agenerator():
for word in sentence.split(): yield word
self._thegen = agenerator()
def __iter__(self): return
On Wed, 18 Apr 2007 15:39:22 +1000, Steven D'Aprano wrote:
I thought that an iterator was any object that follows the iterator
protocol, that is, it has a next() method and an __iter__() method.
...
class Parrot(object):
...
def __init__(self):
self.next = self._next()
self.next
Steven D'Aprano [EMAIL PROTECTED] writes:
class Parrot(object):
def __iter__(self):
return self
def __init__(self):
self.next = self._next()
def _next(self):
for word in Norwegian Blue's have beautiful plumage!.split():
yield word
Clearly
on 18.04.2007 07:39 Steven D'Aprano said the following:
I thought that an iterator was any object that follows the iterator
replace object with instance of a class, i.e. the relevant methods are
looked up in the __class__ not in the instance (I think).
I had the same troubles trying to
On Wed, 18 Apr 2007 16:58:23 +1000, Ben Finney wrote:
Steven D'Aprano [EMAIL PROTECTED] writes:
class Parrot(object):
def __iter__(self):
return self
def __init__(self):
self.next = self._next()
def _next(self):
for word in Norwegian Blue's have
On Wed, 18 Apr 2007 06:13:39 +, I V wrote:
On Wed, 18 Apr 2007 15:39:22 +1000, Steven D'Aprano wrote:
I thought that an iterator was any object that follows the iterator
protocol, that is, it has a next() method and an __iter__() method.
[snip]
i.e., just rename your _next function to
On Apr 18, 3:32 am, Steven D'Aprano [EMAIL PROTECTED]
wrote:
On Wed, 18 Apr 2007 06:13:39 +, I V wrote:
On Wed, 18 Apr 2007 15:39:22 +1000, Steven D'Aprano wrote:
I thought that an iterator was any object that follows the iterator
protocol, that is, it has a next() method and an
Steven D'Aprano wrote:
class SortedDict(dict):
def __iter__(self):
for key in sorted(self.keys()):
yield key
Note that using sorted(self) does not work.
That's because sorted() invokes __iter__() if present. To prevent the
recursion you can explicitly invoke
Stefan Rank schrieb:
on 18.04.2007 07:39 Steven D'Aprano said the following:
I thought that an iterator was any object that follows the iterator
replace object with instance of a class, i.e. the relevant methods are
looked up in the __class__ not in the instance (I think).
I had the same
class Parrot(object):
def __iter__(self):
return self
def __init__(self):
Typo right here
self.next = self._next()
write:
self.next = self._next
no parenthesis.
def _next(self):
for word in Norwegian Blue's have beautiful
Sorry, my previous post was incomplete. I didn't realized that you
implemented _next() as a generator funcition. Besides changing
__init__() from
self.next = self._next()
to
self.next = self._next
you need to implement __iter__() as:
return self.next()
class Parrot(object):
Steven D'Aprano [EMAIL PROTECTED] wrote:
I thought that an iterator was any object that follows the iterator
protocol, that is, it has a next() method and an __iter__() method.
The special methods need to be on the type -- having attributes of those
names on the instance doesn't help (applies
I find myself perplexed as to this behaviour.
You can not iterate over a dead object!
--
http://mail.python.org/mailman/listinfo/python-list
On Apr 18, 10:36 am, [EMAIL PROTECTED] wrote:
I find myself perplexed as to this behaviour.
You can not iterate over a dead object!
It's not dead, it's restin'. All shagged out over a long squak.
--
http://mail.python.org/mailman/listinfo/python-list
On Apr 18, 8:50 am, [EMAIL PROTECTED] (Alex Martelli) wrote:
The special methods need to be on the type -- having attributes of those
names on the instance doesn't help (applies to all special methods in
the normal, aka newstyle, object model; legacy, aka classic, classes,
work by slightly
An iterator is an object with a .__iter__ method that returns self and a
.next method that either returns an object or raises StopIteration.
One very good way to get an iterator from an iterable is for .__iter__ to
be a generator function. When called, it returns an generator with
.__iter__
7stud [EMAIL PROTECTED] wrote:
...
Can you explain some of the details of why this code fails:
...
def next(self):
for word in Norwegian Blue's have beautiful
plumage!.split():
yield word
Sure, easily: a loop like for x in y: binds an unnamed temporary
variable
Hi,
Thanks for the responses.
7stud [EMAIL PROTECTED] wrote:
Can you explain some of the details of why this code fails:
---
class Parrot(object):
def __iter__(self):
return self
def __init__(self):
self.next = self.next().next
def next(self):
for
I thought that an iterator was any object that follows the iterator
protocol, that is, it has a next() method and an __iter__() method.
But I'm having problems writing a class that acts as an iterator. I have:
class Parrot(object):
def __iter__(self):
return self
def
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