I can't understand why this code cause error. please help

Yasuhiko:

I'm not sure what error you received, but it looks like you are missing the last couple steps.

Part 1 of 3: Split available and assign to sundaes - YOU DID THIS

Part 2 of 3: Create variable called menu and set it to the string - YOU DID THIS

Part 3 of 3: Combine sundaes into a new variable called display_menu

Step A of part 3. Create variable display_menu and rejoin each item in sundaes with a comma and space.

display_menu =  ', '.join(sundaes)

Step B of part 3: Reassign the menu variable to use existing and format() to replace the placeholder with display_menu string.

menu = menu.format(display_menu)

I acknowledge your kindness. I'm not good at English. So I did not understand what Question intended to. Now I understand. Thanks for your help