input: Write a function to sort a dictionary by its values in ascending order.
  assert sort_dict_by_values({'Apple':1, 'Strawberry':4, 'Banana':3, 'Grapes':2}) == {'Apple': 1, 'Grapes': 2, 'Banana': 3, 'Strawberry': 4}
  assert sort_dict_by_values({'a':5, 'b':1, 'c':3, 'd':2}) == {'b': 1, 'd': 2, 'c': 3, 'a': 5}
  assert sort_dict_by_values({'x':7, 'y':8, 'z':0}) == {'z': 0, 'x': 7, 'y': 8}
output: def sort_dict_by_values(d):
      return dict(sorted(d.items(), key=lambda item: item[1]))