def delivery_tax():
    district = input("Please type your district to calculate delivery tax: ")
    tax = database.delivery_tax(district)
    if not tax[0]:
        print("Sorry, we do not send to this district")
        return False
    else:
        print("Your delivery tax will be " + str(tax[1]))
        return True
 def test_delivery_tax_unexisting_district(self):
     self.assertEqual((False, 0), database.delivery_tax('Lulin'))
 def test_delivery_tax_existing_district(self):
     database.add_district('Lulin', 4)
     self.assertEqual((True, 4), database.delivery_tax('Lulin'))