input: Write a python function to compute the dot product of two lists.
  assert dot_product([1, 2, 3], [4, 5, 6]) == 32
  assert dot_product([7, 8, 9], [10, 11, 12]) == 278
  assert dot_product([2, 4, 6], [3, 4, 5]) == 46
output: def dot_product(list1, list2):
      return sum(x * y for x, y in zip(list1, list2))