[Python-ideas] csv.DictReader could handle headers more intelligently.

[Eric V. Smith]

On 01/29/2013 07:35 AM, Mark Hackett wrote:
> On Tuesday 29 Jan 2013, Steven D'Aprano wrote:
>>> If it dropped the columns and shouldn't have, then the results will be
>>> seen to be wrong anyway, so there's not a huge amount of need for this.
>>
>> You cannot assume that the caller knows that there are duplicated column
>>  names
>>
> 
> You cannot assume they wanted them as a list.
> 
> You cannot assume that duplicate replacement is what they want.
> 
> If someone is using a csv file with header names they have never read, how are 
> they going to use the data? They won't even know the name to access the value 
> in the dictionary! So I discard the claim that the caller may not know the 
> column names are duplicated. They have to know what the headers are to use 
> DictReader.

Not true: I process some csv files just to translate them into another
format, say tab delimited. I don't care about the column names, but
dropping columns would sure bother me. I don't think any of the files
I've processed have duplicate columns, but I wouldn't swear to it. And
if they did, that would be an error I'd like to know about.

Eric.