[CSV] Re: First Cut at CSV PEP

[Cliff Wells]

On Tue, 2003-01-28 at 16:15, Dave Cole wrote:
> >>>>> "Andrew" == Andrew McNamara <andrewm at object-craft.com.au> writes:
> 
> >> I think it is important to keep in mind the users of the module who
> >> are not expert in the various dialects of CSV.  If presented with a
> >> flat list of all options supported they are going to engage in a
> >> fair amount of head scratching.
> >> 
> >> If we try to make things easier for users by mirroring the options
> >> that their application presents then they are going to have a much
> >> easier time working out how to use the module for their specific
> >> problem.  By limiting the available options based upon the dialect
> >> specified by the user we will be doing them a favour.
> >> 
> >> The point of the 'raw' dialect is to expose the full capabilities
> >> of the raw parser.  Maybe we should use None rather than 'raw'.
> 
> Andrew> My feeling is that this simply changes the shape of the
> Andrew> complexity without really helping.
> 
> Andrew> I think we should just stick with the "a dialect is a set of
> Andrew> defaults" idea.
> 
> Fair enough.

Whew.

> 
> Instead of limiting the tweakable options by raising an exception we
> could have an interface which allowed the user to query the options
> normally associated with a dialect.
> 
> >> Hmm...  What would be the best way to handle Excel TSV.  Maybe a
> >> new dialect 'excel-tsv'?

So are we leaning towards dialects being done as simple classes?  Will
'excel-tsv' simply be defined as 

class excel_tsv(excel_2000):
    delimiter = '\t'

with a dictionary for lookup:

settings = { 'excel-tsv': excel_tsv,
             'excel-2000': excel_2000, }

? 

> Andrew> When saving, Excel97 calls this "Text (Tab delimited)", so
> Andrew> maybe "excel-tab" would be clear enough. CSV is "CSV (Comma
> Andrew> delimited)".
> 
> Yup.
> 
> Andrew> On import, it seems to just guess what the file is - I
> Andrew> couldn't see a way under Excel97 to specify.
> 
> Some kind of sniffing going on.
> 
> Should we have a sniffer in the module?

This hasn't been brought up, but of course one of the major selling
points of DSV is the "sniffing" code.  However, I think I'm with Dave on
having another layer (CSVutils) that would contain this sort of thing.

> >> I am not saying that the wrapper should absolutely prevent someone
> >> from using options not available in the application.  If you want
> >> to break the dialect then maybe it should be a two step process.
> >> 
> >> csvwriter = csv.writer(file("newnastiness.csv", "w"), dialect='excel2000')
> >> csvwriter.setparams(delimiter='"')
> 
> Andrew> This strikes me as B&D.
> 
> Just what are you trying to imply by that? :-)

We should probably leave people's personal issues out of this ;)

-- 
Cliff Wells, Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308  (800) 735-0555 x308