a_dictionary = {}
a_dictionary["a"] = [1, 2, 3]
a_dictionary["b"] = [4, 5, 6]
a_dictionary["c"] = [7, 8, 9]
print(a_dictionary)
{'a': [1, 2, 3], 'b': [4, 5, 6], 'c': [7, 8, 9]}