Did I use the enumerate function correctly?

Question

At the end of the 'Shopping List Take Three' video, Kenneth suggests finding a way to use the enumerate function instead of the indexes he uses in the video. My program here seems to work OK but just wanted someone to check it for me. I wasn't sure if that 'value' portion is part of the enumerate function.

import os

shopping_list = []

def clear_screen():
    os.system("cls" if os.name == "nt" else "clear")

def show_help():
    clear_screen()
    print("What should we pick up at the store?")
    print("""
Enter 'DONE' to stop adding items.
Enter 'SHOW' to show current items.
Enter 'HELP' to see a help message about special commands.
""")

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:
        position = abs(int(position))
    except ValueError:
        position = None
    if position is not None:
        shopping_list.insert(position-1, item)
    else:
        shopping_list.append(new_item)

    show_list()

def show_list():

    clear_screen()

    print("Here's your list:")

    for item, value in enumerate(shopping_list, 1):
        print(item, value)

    print("-"*10)    

show_help()

while True:
    new_item = input("> ")
    if new_item.upper() == 'DONE' or new_item.upper() == 'QUIT':
        break
    elif new_item.upper() == 'SHOW':
        show_list()
        continue
    elif new_item.upper() == 'HELP':
        show_help()
        continue
    else:
        add_to_list(new_item)

show_list()

Answer 1 · 2018-07-02T20:16:22Z

July 2, 2018 8:16pm

Nice work... you are very close! The enumerate method has been around since Python 2.3 but it is not always taught in introductory lessons.

https://docs.python.org/2.3/whatsnew/section-enumerate.html

In your code, if you reverse the order of value and item you will get it.

I am going to use INDEX rather than value, since I think index is a little more straightforward example of how it works.

Python 3.6.4 (v3.6.4:d48eceb, Dec 19 2017, 06:04:45) [MSC v.1900 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> my_list = ['eggs','bread','cheese','milk']
>>>
>>> # without enumerate, you need to have a separate index variable and increment statement
... index = 1
>>> for item in my_list:
...     print(index, item)
...     index +=1
...
1 eggs
2 bread
3 cheese
4 milk
>>> # with enumerate, you save two lines of code and your code is arguably better
... for index, item in enumerate(my_list, 1):
...     print(index, item)
...
1 eggs
2 bread
3 cheese
4 milk

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chailatte

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Did I use the enumerate function correctly?

1 Answer

Jeff Muday

Jeff Muday

chailatte

chailatte