IOError and Try Again to loop the loop.

[Chris Rebert]

On Sun, Jul 11, 2010 at 8:13 PM, The Danny Bos <dannybos at gmail.com> wrote:
> Thanks gang,
> I'm gonna paste what I've put together, doesn't seem right. Am I way
> off?
>
> Here's my code.
>  - It goes through a table Item
>  - Matches that Item ID to an API call
>  - Grabs the data, saves it and creates the thumbnail
>  - It dies due to Timeouts and Other baloney, all silly, nothing code
> based.
>
> items = Item.objects.all().filter(cover='').order_by('-reference_id')
> for item in items:
>        url = "http://someaddress.org/books/?issue=%s" % item.reference_id
>
>        url_array = []
>        url_open = urllib.urlopen(url)
>        url_read = url_open.read().decode('utf-8')
>
>        try:
>                url_data = simplejson.loads(url_read)
>                url_array.append(url_data)
>
>                for detail in url_array:

Unless I'm missing something, there's no need for url_array to exist
at all. It starts out empty, you append url_data to it, then you
iterate over it as `detail`; and you don't touch it anywhere else in
the loop. Just s/detail/url_data/ and excise url_array altogether. As
a bonus, there'll be one less level of indentation.

Also, the reason your code doesn't work (currently, it just skips to
the next item upon error) is because you're missing a surrounding
`while True` loop (and associated embedded `break`) to do the retrying
(see my or MRAB's examples).

Additionally, stylistically I'd prefer the try-excepts to cover
smaller and more targeted areas of the code, rather than having one
giant blanket one for the entire loop body; perhaps that's just me
though.

Cheers,
Chris
--
How exactly does one acquire a prenominal "The"?
http://blog.rebertia.com