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Python Python Basics (2015) Shopping List App Second Shopping List App

Valerio Versace
Valerio Versace
11,319 Points
Posted by Valerio Versace
Valerio Versace
11,319 Points

Shopping list While loop

Kenneth does it like this:

show_help()

while True:
    new_item = input("> ")
    if new_item == "DONE":
        break
    elif new_item == "HELP":
        show_help()
        continue
    elif new_item == "SHOW":
        print_list()
        continue
    add_to_list(new_item)

print_list()

Why all those "continue"?

Wouldn't it be better to do it like this?

show_help()

while True:
    new_item = input("> ")
    if new_item == "DONE":
        break
    elif new_item == "HELP":
        show_help()
    elif new_item == "SHOW":
        print_list()
    else:
        add_to_list(new_item)

print_list()

2 Answers

Evan Demaris
Evan Demaris
64,262 Points
Evan Demaris
Evan Demaris
64,262 Points

Hi Valerio,

I think the reason why Kenneth worked his code that way is that he's trying to teach how continue works. Your code would be more efficient, though.

Valerio Versace
Valerio Versace
11,319 Points
Valerio Versace
Valerio Versace
11,319 Points

Cool, didn't think about that! Makes sense.

Colby Work
Colby Work
20,422 Points
Colby Work
Colby Work
20,422 Points

without the continue, the words HELP and SHOW get added to the list. he briefly explains it at 3:40.

Evan Demaris
Evan Demaris
64,262 Points

Actually, that isn't the case with Valerio's code.

Valerio moved the add_to_list(new_item) into an else block, so it won't be executed unless DONE, HELP and SHOW are all != to new_item.

Colby Work
Colby Work
20,422 Points

ah... i see that