[Python-ideas] csv.DictReader could handle headers more intelligently. (original) (raw)

Ethan Furman ethan at stoneleaf.us
Fri Jan 25 04:20:23 CET 2013

On 01/24/2013 02:47 AM, Mark Hackett wrote:

On Thursday 24 Jan 2013, Steven D'Aprano wrote:

I'm not sure this behavior merits the all-caps "AS EXPECTED" label. It's not terribly surprising once you sit down and think about it, but it's certainly at least a little unexpected to me that data is being thrown away with no notice. It's unusual for errors to pass silently in python. Yes, we should not forget that a CSV file is not a dict. Just because DictReader is implemented with a dict as the storage, doesn't mean that it should behave exactly like a dict in all things. Multiple columns with the same name are legal in CSV, so there should be a reader for that situation. But just because it's reading a csv file, we shouldn't change how a dictionary works if you add the same key again.

The proposal is not to change how a dict works, but what the proper response is for DictReader when a duplicate key is found.

Ethan

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