input: Write a function to create a dictionary from a list where keys and values are the elements of the list using a dictionary comprehension.
  assert create_dict_from_list([1, 2, 3, 4]) == {1: 1, 2: 2, 3: 3, 4: 4}
  assert create_dict_from_list(['a', 'b', 'c']) == {'a': 'a', 'b': 'b', 'c': 'c'}
  assert create_dict_from_list([]) == {}
output: def create_dict_from_list(lst):
      return {x: x for x in lst}