How to prevent appending same tuples when inheriting fields.selection field

Question

I have this but when I update my module it appends the same tuple

class account_journal_inherit(osv.osv):

_inherit='account.journal'

def __init__(self, pool, cr):

_type=super(account_journal_inherit, self)._columns['type'].selection
_type.append(('credit_payment', 'Prepaid Credit'))

return super(account_journal_inherit, self).__init__(pool,cr)

Thanks

Deepa Venkatesh · Answer

Could you elobrate more...

or you trying to say you want your own set of typle values for selection field "type" ?

If So then Override it... Re-define type under columns in your custom module.. that one can override its original values.. or extend it too...