def item_tax(item, discounts):
 price = item.get_price_per_item(discounts=discounts)
 return (u'US::%s:y' % price.tax)

def item_tax ( item , discounts ) : price = item . get_price_per_item ( discounts = discounts ) return ( u'US::%s:y' % price . tax )
for some countries you need to set tax info read more: URL .