csv: No fields, or one field?

[Neil Cerutti]

On 2012-04-26, Tim Roberts <timr at probo.com> wrote:
> Neil Cerutti <neilc at norwich.edu> wrote:
>
>>Is there an explanation or previous dicussion somewhere for the
>>following behavior? I haven't yet trolled the csv mailing list
>>archive, though that would probably be a good place to check.
>>
>>Python 3.2 (r32:88445, Feb 20 2011, 21:29:02) [MSC v.1500 32 bit
>>(Intel)] on win 32
>>Type "help", "copyright", "credits" or "license" for more information.
>>>>> import csv
>>>>> next(csv.reader(['""\r\n']))
>>['']
>>>>> next(csv.reader(['\r\n']))
>>[]
>>
>> I hoped or assumed that the 2nd invocation should have the
>> same result as the first.
>
> Really?  That's not at all what I would have expected.  The
> first line contains one field.  The second line contains 0
> fields.  It's consistent, and syntactically valid.
>
>> I admit a blank, one-field csv record just isn't very
>> insteresting, but isn't this a special case that ought to be
>> documented? 
>
> But that's what you have in the first line, and the reader has
> returned to you a list containing one (empty) string.
>
> I just don't see your interpretation.  The results are exactly
> what I would have expected.

I made the following wrong assumption about the csv EBNF
recognized by Python (ignoring record seps):

record -> field {delim field}

There's at least some csv "standard" documents requiring my
interprestion, e.g.,

http://mastpoint.curzonnassau.com/csv-1203/CSV-1203.pdf

but by no means all. That's why I thought it might be something
that should be documented rather than discovered.

-- 
Neil Cerutti