Can someone explain to me the commands [0][1][2] in the code below and how they work

Question

if __name__ == '__main__':
    N = int(input())
    my_list = []  # Initialize an empty list to perform operations on.

    for _ in range(N):
        command = input().split()  # Read the command as a space-separated string.
    
        if command[0] == 'insert':
            my_list.insert(int(command[1]), int(command[2]))
        elif command[0] == 'print':
            print(my_list)
        elif command[0] == 'remove':
            my_list.remove(int(command[1]))
        elif command[0] == 'append':
            my_list.append(int(command[1]))
        elif command[0] == 'sort':
            my_list.sort()
        elif command[0] == 'pop':
            my_list.pop()
        elif command[0] == 'reverse':
            my_list.reverse()

#ChatGP isn't explaining it properly, I want to understand the commands 0,1,2 and how they work

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. — Community, Sep 02 '23 at 09:25

Muz · Answer 1 · 2023-09-02T08:11:51.963

0

command is array (list) of strings.

if given input is "insert 0 5" then

command = ["insert", "0", "5"]

so command[0] is first element of command (command[0] = "insert"), command[1] is second etc.

these numbers in square brackets are called indexes

more about it: https://www.freecodecamp.org/news/python-find-in-list-how-to-find-the-index-of-an-item-or-element-in-a-list/

edited Sep 02 '23 at 08:11

answered Sep 02 '23 at 08:10

Muz

1
2

score 0 · Answer 2 · answered Sep 02 '23 at 09:39

I see what problem you are facing with. The code the first element of the command list (command[0]) to determine what operation to perform.

    if command[0] == 'insert':
        my_list.insert(int(command[1]), int(command[2]))
    elif command[0] == 'print':
        print(my_list)
    elif command[0] == 'remove':
        my_list.remove(int(command[1]))
    elif command[0] == 'append':
        my_list.append(int(command[1]))
    elif command[0] == 'sort':
        my_list.sort()
    elif command[0] == 'pop':
        my_list.pop()
    elif command[0] == 'reverse':
        my_list.reverse()

If command[0] is 'insert', it inserts an integer into my_list at the specified index.
If command[0] is 'print', it prints the current contents of my_list.
If command[0] is 'remove', it removes the first occurrence of a specified integer from my_list.
If command[0] is 'append', it appends an integer to the end of my_list.
If command[0] is 'sort', it sorts my_list in ascending order.
If command[0] is 'pop', it removes and returns the last element of my_list.
If command[0] is 'reverse', it reverses the order of elements in my_list. Each command going to effect to list. For example if user enters 1 for N. Then enter insert 0 23 for command, it will insert the integer 23 at index 0 of my_list.

Final code:

if __name__ == '__main__':
N = int(input("How many command do you want to enter: "))
my_list = [1, 8, 9, 31, 25, 65]  # we can add some elements

for _ in range(N):
    command = input("Enter your commands: ").split()  # Read the command as a space-separated string.

    if command[0] == 'insert':
        my_list.insert(int(command[1]), int(command[2]))
    elif command[0] == 'print':
        print(my_list)
    elif command[0] == 'remove':
        my_list.remove(int(command[1]))
    elif command[0] == 'append':
        my_list.append(int(command[1]))
    elif command[0] == 'sort':
        my_list.sort()
    elif command[0] == 'pop':
        my_list.pop()
    elif command[0] == 'reverse':
        my_list.reverse()

print(my_list)

Can someone explain to me the commands [0][1][2] in the code below and how they work

2 Answers2