how to add key if then in dictionary and then update python code example

Example 1: 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++'}

Example 2: append dictionary python

>>> d1 = {1: 1, 2: 2}
>>> d2 = {2: 'ha!', 3: 3}
>>> d1.update(d2)
>>> d1
{1: 1, 2: 'ha!', 3: 3}