python newbie - question about lexical scoping

[John Machin]

On Dec 1, 4:47 pm, Matt Barnicle <ma... at wageslavery.org> wrote:
> hi everyone..  i've been chugging along learning python for a few months
> now and getting answers to all needed questions on my own, but this one
> i can't figure out nor can i find information on the internet about it,
> possibly because i don't understand the right words to type into google..
>
> i have a very common scenario and need to know the python way to do it.
> take this example loop:
>
> comments = []
> for row in rows:
>     comment = models.comment()

Insert here:
      print type(comment), id(comment), repr(row[:2])

>     comment.author = row[1]
>     comment.text = row[0]
>     comments.append(comment)
>
> the problem is that when i go to retrieve the comments later, they are
> all the same object!  i assume this is due to there being no lexical
> scoping?  so what is the solution to this?

And the attributes of the "same object" match the first two elements
of which input row:
(a) rows[0]
(b) rows[-1]
(c) some other row
(d) you can't tell because all input rows have the same value in each
of row[0] and row[1]
(e) none of the above?

It's nothing to do with lexical scoping, at least in the code that
you've shown us, which has no apparent problems. You need to show us
the code for the models.comment function/method/class. Possibly it is
returning the same object each time it is invoked (answer (b) above);
the above print statement will help investigate that possibility, plus
the possibility that the objects are not the same objects, but are
different objects with the same attributes (answer (d) above). Also
show us the code for retrieving the comments later; possibly you are
retrieving the same element of the comments list each time. Use this:
    print [id(x) for x in comments]
to verify your assertion that they are all the same object.

Cheers,
John