如何从 Python 中的列表列表中删除索引？

Question

I am trying to remove a whole index in a list of lists (John in this case), as seen here where the list is called player_list :

player_list = [['Bruce Wayne', 5, 5, 0, 0, 100, 15], 
               ['Jessica Jones', 12, 0, 6, 6, 10, 6], 
               ['Johnny Rose', 6, 2, 0, 4, 20, 10], 
               ['Gina Linetti', 7, 4, 0, 3, 300, 15], 
               ['Buster Bluth', 3, 0, 2, 1, 50, 1], 
               ['John', 0, 0, 0, 0, 100, 0]]

However, when I run the function remove_player :

def remove_player(player_list, name):
    check = find_player(player_list, name)
    new_list = []

    if check == -1:
        print(name, "is not found in players")
    else:
        for i in range(len(player_list)):
            if player_list[i] != player_list[check]:
                new_list.append(player_list[i])
        player_list = new_list
           
    print(name, "has sucessfully been removed.")

and the function: find_player :

def find_player(player_list, name):
    found = -1
    index = 0

    while index < len(player_list) and found == -1:
        if name == player_list[index][0]:
            found = index
        index += 1
    return found
             

Where name comes from:

removed_player = input("Please enter name: ")
remove = remove_player(player_list, removed_player)

It does remove the index from the list, however it still is printed in the table I have created here which is not what I want it to do:

===========================================================
-                     Player Summary                      -
===========================================================
-                            P  W  L  D    Chips    Score -
===========================================================
- Bruce Wayne                5  5  0  0      100       15 -
-----------------------------------------------------------
- Jessica Jones             12  0  6  6       10        6 -
-----------------------------------------------------------
- Johnny Rose                6  2  0  4       20       10 -
-----------------------------------------------------------
- Gina Linetti               7  4  0  3      300       15 -
-----------------------------------------------------------
- Buster Bluth               3  0  2  1       50        1 -
-----------------------------------------------------------
- John                       0  0  0  0      100        0 -
-----------------------------------------------------------
===========================================================

The function I have created for the table, display_players(player_list) :

def display_players(player_list):
    print("===========================================================")
    print("-", format("Player Summary", ">34s"), format("-", ">22s"))
    print("===========================================================")
    print("-", format("P", ">28s"), format("W", ">2s"), format("L", ">2s"), format("D", ">2s"), format("Chips", ">8s"), format("Score", ">8s"), format("-", ">1s"))
    print("===========================================================")

    for i in range(len(player_list)):
        print("-", format(str(player_list[i][0]), "<25s"), format(str(player_list[i][1]), ">2s"), format(str(player_list[i][2]), ">2s"), format(str(player_list[i][3]), ">2s"), format(str(player_list[i][4]), ">2s"), format(str(player_list[i][5]), ">8s"), format(str(player_list[i][6]), ">8s"), ("-"))
        print("-----------------------------------------------------------")

    print("===========================================================")

I'm not sure why it is not working. Please note I am not allowed to use any of the list functions aside from list_name.append(item) in the remove_player function.

Thank you!

Answer 1

Can you try out this?

player_list = [['Bruce Wayne', 5, 5, 0, 0, 100, 15], 
               ['Jessica Jones', 12, 0, 6, 6, 10, 6], 
               ['Johnny Rose', 6, 2, 0, 4, 20, 10], 
               ['Gina Linetti', 7, 4, 0, 3, 300, 15], 
               ['Buster Bluth', 3, 0, 2, 1, 50, 1], 
               ['John', 0, 0, 0, 0, 100, 0]]

def remove_player(player_list, name):
    return [ player for player in player_list if player[0] != name]

player_list = remove_player(player_list, 'Bruce Wayne')

Answer 2

You can try to use the function pop which is going to delete the specific index.

check = find_player(player_list, name)

if check == -1:
    print(name, "is not found in players")

else:
    player_list.pop(check)
print(name, "has sucessfully been removed.")

Here the doc

list.pop([i])
Remove the item at the given position in the list, and return it. If no index is specified, a.pop() removes and returns the last item in the list. (The square brackets around the i in the method signature denote that the parameter is optional, not that you should type square brackets at that position. You will see this notation frequently in the Python Library Reference.)

Answer 3

Your code is except a little detail working fine. You never change the original player_list . You use it in your function to make new_list and then you assign player_list to it, but all this is inside the function and you don't return it to get access to it outside of your function.

Here is your remove_player function:

def remove_player(player_list, name):
    check = find_player(player_list, name)
    new_list = []

    if check == -1:
        print(name, "is not found in players")
    else:
        for i in range(len(player_list)):
            if player_list[i] != player_list[check]:
                new_list.append(player_list[i])
        player_list = new_list
           
    print(name, "has sucessfully been removed.")
    return player_list

I only added the return statement at the end.

Now when calling this:

removed_player = input("Please enter name: ")
player_list = remove_player(player_list, removed_player)

assign the returned list to player_list and you will see, when printing it, it works.