Hello. About your code snippet:
1. Dance is function that accepts command with or without arguments, calls some function (command name in fact concurs called function) and passes the rest of arguments to it.
2. The first input value (N) is the number of following commands.
3. All commands are applied to list (lis).
Let's analyze the commands and the state of the list:
0. The list is empty: []
1. The number 5 is inserted to the position 0 (list positions are zero-based): [5].
2. The number 10 is insteted to the position 1: [5, 10].
3. The number 6 is inseted to the positon 0: [6, 5, 10].
4. List is printed. Output will be [6, 5, 10].
5. The number 6 is removed from the list: [5, 10].
6. The number 9 is appended (inserted to the end of the list): [5, 10, 9].
7. The number 1 is appended: [5, 10, 9, 1].
8. The list is sorted: [1, 5, 9, 10].
9. The list is printed. Output will be [1, 5, 9, 10].
10. The last element is discarded from the list: [1, 5, 9].
11. The list is reversed: [9, 5, 1].
12. The list is printed. Output will be [9, 5, 1].
Please contact me if you are interested in my bid.