Create or import Carrier selection

Hi,

I try to create a new carrier which has 200 ToCountries. They are the same as another existing Carrier. I didn’t find a way to copy or duplicate+bulk changing the Carrier. So I tried to CSV export Carrier selection, with three columns:
Carrier/ID From Country/ID To Country/ID
and réimport them with the Carrier/ID corrected. This doesn’t work (“Object error in importing the file”).
I tried using Carrier product name and country 3 letters codes too.

How is this possible for a user to create a many-countries Carrier selection without doing a one-by-one line creation?

Since Issue 8817: Add selections One2Many on carrier - Tryton issue tracker it is possible to duplicate the carrier with all of its selection configuration.

I think in your case it makes sense to just duplicate the carrier and change the required values. This will copy all the selection values to new carrier, so there is no need to read them.