input: Write a function to replace the use of a list with a dictionary in the given Python program. If the list is empty, return an empty dictionary.
  assert replace_list_with_dict([1, 2, 3, 4])=={1: 'one', 2: 'two', 3: 'three', 4: 'four'}
  assert replace_list_with_dict([])=={}
output: def replace_list_with_dict(lst):
      if not lst:
          return {}
      return {num: 'one' if num == 1 else 'two' if num == 2 else 'three' if num == 3 else 'four' for num in lst}