In an existing dictionary, what is the function needed to add a value to a corresponding key that has just been added? code example

Example: dictionary in python does not support append operation

dict_append = {"1" : "Python", "2" : "Java"}
dict_append.update({"3":"C++"})  # append doesn't supported in dict 
								 # instead , use update in dict
print(dict_append)
# output : {'1': 'Python', '2': 'Java', '3': 'C++'}