input: Write a python function to calculate the total price of items in a list using a dictionary of prices.
  assert calculate_price(['apple', 'apple', 'orange', 'banana', 'apple']) == 16
  assert calculate_price(['banana', 'banana', 'orange']) == 14
  assert calculate_price(['apple', 'orange']) == 8
output: def calculate_price(items):
      prices = {'apple': 4, 'orange': 6, 'banana': 4}
      total = sum(prices[item] for item in items)
      return total