input: Write a python function to calculate the dot product of two vectors.
  assert dot_product([1, 2, 3], [4, 5, 6]) == 32
  assert dot_product([0, 1, 2], [2, 1, 0]) == 1
  assert dot_product([2, 3], [2, 3]) == 13
output: def dot_product(vector1, vector2):
      return sum(x * y for x, y in zip(vector1, vector2))