input: Write a function to create a dictionary where the key is a number from a given list and the value is the square of that number. If the list is empty, return an empty dictionary.
  assert create_square_dict([1, 2, 3, 4, 5])=={1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
  assert create_square_dict([0, -1, -2, 3, 4])=={0: 0, -1: 1, -2: 4, 3: 9, 4: 16}
  assert create_square_dict([])=={}
output: def create_square_dict(numbers):
      return {num: num**2 for num in numbers}