input: Write a function that takes in a list and prints a dictionary with the elements and the product of each element. The function should be named product_of_list and should return the dictionary. If the list is empty, the function should return an empty dictionary.
  assert product_of_list([7, 8, 5])=={7: 49, 8: 64, 5: 25}
  assert product_of_list([3, 4, 10])=={3: 9, 4: 16, 10: 100}
  assert product_of_list([])=={}
output: def product_of_list(lst):
      result = {}
      for num in lst:
          result[num] = num * num
      return result