python array append extend

1my_list = ['a','b']  
2my_list.append('c') 
3print(my_list)      # ['a','b','c']
4
5other_list = [1,2] 
6my_list.append(other_list) 
7print(my_list)      # ['a','b','c',[1,2]]
8
9my_list.extend(other_list) 
10print(my_list)      # ['a','b','c',[1,2],1,2]