Removing items from list

[slackerman73]

I'm trying to remove an item from the passwords list.

I keep getting Traceback (most recent call last):
passwords.remove(websitetodelete) #This line is where I'm hung up. Trying to remove the websitetodelete from the previous line. I'm sure i'm not referencing the list correctly.
ValueError: list.remove(x): x not in list

Not sure

passwords = [["yahoo","XqffoZeo"],["google","CoIushujSetu"]]

while True:
    print("What would you like to do:")
    print(" 1. Open password file")
    print(" 2. Lookup a password")
    print(" 3. Add a password")
    print(" 4. Save password file")
    print(" 5. Print the encrypted password list (for testing)")
    print(" 6. Quit program")
    print(" 7. Delete a password")
    print("Please enter a number (1-7)")
    choice = input()

    if(choice == '7'): #Delete a password
        print("Which website do you want to delete?")
        for keyvalue in passwords:
            print(keyvalue[0]) #Printing the list of websites for the user to choose from.
        websitetodelete = input()  #Accepting the user's input for the website to remove.
        passwords.remove(websitetodelete)  #This line is where I'm hung up.  Trying to remove the websitetodelete from the previous line.  I'm sure i'm not referencing the list correctly.

[ichabod801]

You had this exact same problem in your last post. The answer is still the same. 'websitetodelete' is a string. The items in passwords are lists. You can't delete an item that isn't in the list, so you can't delete a string from a list of lists. You need to delete the [website, password] list, or you need to reconstruct the list, possibly like so:

passwords = [pair for pair in passwords if pair[0] != websitetodelete]

[slackerman73]

This works but we've not learned how to reconstruct a list.

How would I delete the [website, password] list? Would I need to take the given index of the website and delete whatever list that website is in? I'm probably going to run into the same issues where the input is a string and the list is not, as you so kindly pointed out to me. :)

[Malt]

you can try like,

for values in passwords:
    if websitetodelete in values:
        passwords.remove(values)

This would remove [website,password] list from the passwords list

[ichabod801]

That's not a good solution, you don't want to modify a list while you are looping over it.

If you haven't done list comprehensions, you can reconstruct a list with a for loop:

new_pass = []
for site_pass in passwords:
    if site_pass[0] != websitetodelete:
        new_pass.append(site_pass)
passwords = new_pass

[nilamo]

Since this is basically a collection of key-value pairs (website to password), you could also use a dict, and then use dict.pop() to remove them.

>>> sites = {"yahoo": "yahoo_password", "google": "spam-is-Ta$ty"}
>>> sites
{'yahoo': 'yahoo_password', 'google': 'spam-is-Ta$ty'}
>>> "yahoo" in sites
True
>>> sites.pop("yahoo")
'yahoo_password'
>>> sites
{'google': 'spam-is-Ta$ty'}

[ichabod801]

He said in another post that he has to use a list for this.

[ibreeden]

But pop() also works on lists.

>>> passwords = [["yahoo","XqffoZeo"],["google","CoIushujSetu"]]
>>> passwords.pop(1)
['google', 'CoIushujSetu']
>>> passwords
[['yahoo', 'XqffoZeo']]

So find the index of the site to be deleted and use passwords.pop(index).

[Clunk_Head]

I'm trying to remove an item from the passwords list.

I keep getting Traceback (most recent call last):
passwords.remove(websitetodelete) #This line is where I'm hung up. Trying to remove the websitetodelete from the previous line. I'm sure i'm not referencing the list correctly.
ValueError: list.remove(x): x not in list

Not sure

passwords = [["yahoo","XqffoZeo"],["google","CoIushujSetu"]]

while True:
    print("What would you like to do:")
    print(" 1. Open password file")
    print(" 2. Lookup a password")
    print(" 3. Add a password")
    print(" 4. Save password file")
    print(" 5. Print the encrypted password list (for testing)")
    print(" 6. Quit program")
    print(" 7. Delete a password")
    print("Please enter a number (1-7)")
    choice = input()

    if(choice == '7'): #Delete a password
        print("Which website do you want to delete?")
        for keyvalue in passwords:
            print(keyvalue[0]) #Printing the list of websites for the user to choose from.
        websitetodelete = input()  #Accepting the user's input for the website to remove.
        passwords.remove(websitetodelete)  #This line is where I'm hung up.  Trying to remove the websitetodelete from the previous line.  I'm sure i'm not referencing the list correctly.

If this is the way that the assignment requires that you do it and you do not understand list reconstruction then you need to find the entry that contains the website using a loop.
You've got everything else right, but you are trying to delete something that doesn't exist in the list. The lists remove function must contain the entire entry, where as you are only trying to remove part.

"yahoo" # This is what you have

["yahoo","XqffoZeo"] # This is what you need

Here is the loop that will give you the complete entry

for combo in passwords: # Read each website / password combo in the passwords list
    if combo[0] == websitetodelete: # If it matches the site the user specified
        websitetodelete = combo # Update the query to contain the entire combo
        break # Stop looking because you've found it
passwords.remove(websitetodelete) # Now this command will work