class ShoppingCart(object):
  def __init__(self):
    self.items = []

  def add(self, item, price):
    for cart_item in self.items:
      # Since we found the item, we increment
      # instead of append
      if cart_item.item == item:
        cart_item.q += 1
        return self

    # If we didn't find, then we append
    self.items.append(Item(item, price))
    return self

  def item(self, index):
    return self.items[index - 1].item

  def price(self, index):
    return self.items[index - 1].price * self.items[index - 1].q

  def total(self, sales_tax):
    sum_price = sum([item.price * item.q for item in self.items])
    return sum_price * (1.0 + sales_tax / 100.0)

  def __len__(self):
    return sum([item.q for item in self.items])

class Item(object):
  def __init__(self, item, price, q=1):
    self.item = item
    self.price = price
    self.q = q




import unittest
#from cart import *

class ShoppingCartTest(unittest.TestCase):
  def setUp(self):
    self.cart = ShoppingCart().add("tuna sandwich", 15.00) \
                              .add("tuna sandwich", 15.00)

  def test_length(self):
    self.assertEquals(2, len(self.cart))

  def test_item(self):
    self.assertEquals("tuna sandwich", self.cart.item(1))

  def test_price(self):
    self.assertEquals(30.00, self.cart.price(1))

  def test_total_with_sales_tax(self):
    self.assertAlmostEquals(32.78, self.cart.total(9.25), 2)

  def test_total_should_fail(self):
    self.assertNotEqual(13.00, self.cart.total(10), 2)

  def test_should_have_index_error(self):
    self.assertRaises(IndexError, self.cart.item, 5)

if __name__ == "__main__":
  unittest.main()