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Python Python Collections (2016, retired 2019) Lists Removing Items From A List

Camray Austin
PLUS
Camray Austin
Courses Plus Student 725 Points
Posted by Camray Austin
Camray Austin
Courses Plus Student 725 Points

How to make code print("this item is not in your shopping list")? Having trouble with this really thought it was easy. 

import os


shopping_list = []
def clear():
    os.system("cls" if os.name == "nt" else "clear")

def show_help():
    clear()
    # print out instructions on how to use the app
    print("What items do you wish to add? ")
    print("""
Enter 'DONE' to stop adding items. 
Enter 'HELP' for this help.
Enter 'SHOW' to see current list.
Enter 'REMOVE' to delete a item from your list.
""")
def add_to_list(item):
    show_list()
    if len(shopping_list):
        position = input("Where should i add {}?\n"
                         "Press ENTER to add to the end of the list\n"
                         "> ".format(item))
    else:
        position = 0
    try:
        postion = abs(int(position))
    except ValueError:
        position = None
    if position is not None:
        shopping_list.insert(postion-2,item) 
    else:
        shopping_list.append(new_item)

    show_list()


def show_list():
    clear()

    print("Here's your list:")

    index = 1

    for item in shopping_list:
        print("{}. {}".format(index, item)) 
        index += 1

    print("-" * 10)


def remove_from_list(item):
    show_list()
    delete =input('What do you want to delete?\n> ')
    try:
        shopping_list.remove(delete)
    except ValueError:
        pass

    show_list()


show_help()


while True:
    new_item = input("> ")
# be able to quit the app   
    if new_item.upper()== 'DONE' or new_item.upper() == 'QUIT':
        break
    elif new_item.upper() == "HELP":
        show_help()
        continue 
    elif new_item.upper() == "SHOW":
        show_list()
        continue
    elif new_item.upper() == 'REMOVE':
        remove_from_list()

    else:
        add_to_list(new_item)

show_list()
David Bath
David Bath
25,940 Points
David Bath
David Bath
25,940 Points

I don't understand your remove_from_list function. It uses a couple of variables that don't exist anywhere else in the code (word and secret_word).

3 Answers

Wesley Trayer
Wesley Trayer
13,812 Points
Wesley Trayer
Wesley Trayer
13,812 Points

In the "remove_from_list" function, after the

delete =input('What do you want to delete?\n> ')

add

if delete in shopping_list:

indent the try block and add an else to the if statement after the try block

   else:

       print("this item is not in your shopping list")
Mathew V L
Mathew V L
2,910 Points

Sorry for the old response, but this doesn't work for me. This is my code: 

def remove_from_list():
    show_list()
    what_to_remove = input("What items do you want to remove you're list?")
    if what_to_remove in shopping_list:
        try:
            shopping_list.remove(what_to_remove)
    else: 
        print("Not Found")

I keep getting indentation error, any help would be great!

Wesley Trayer
Wesley Trayer
13,812 Points
Wesley Trayer
Wesley Trayer
13,812 Points

Hey Mathew V L, an indentation error often occurs if the indentation is not consistent throughout the code. I would check the "spaces" option in the bottom right corner of workspaces, assuming you're using workspaces, it is usually set to "spaces: 4". If it is set to something else, say "spaces: 2" or "tabs 4", and it was set to "spaces: 4" while you were writing the rest of the code, it will throw an indentation error.

Also, I can't see the indentation of your code, because of the way it's formatted. If you want your code to look like it does in workspaces,

"Like this!"

check out the "Code" section of the "Markdown Cheatsheet".

Hope this helps!

boi
boi
14,242 Points
boi
boi
14,242 Points

Bro Camray (or sis).

Your code is perfectly fine, the only problem is that in the remove_from_list function you gave it an argument "item" which is invalid because you are asking for the argument from the user. The user will tell you what he whats to "remove" and that can be anything not necessarily an "item", that is why you used TRY block. Just write 

def remove_from_list():
    show_list()
    delete =input('What do you want to delete?\n> ')
    try:
        shopping_list.remove(delete)
    except ValueError:
        pass

    show_list()

and secondly, put your 

delete = input('What do you want to delete?\n>')

in the TRY block like this, for better "beginner readability".

def remove_from_list():
    show_list()
    try:
        delete =input('What do you want to delete?\n> ')
        shopping_list.remove(delete)
    except ValueError:
        pass

    show_list()

And that's done, your code is perfectly fine.