I don't know where I went wrong in this question. I ran all the code through python 3.51 and it didn't have any error?

For your second day of coding your code is quite impressive, this challenge is somewhat infamous for frustrating quite a large amount of users due to it's instructions being pretty confusing, so I don't blame you for being uncertain about what the challenge wants.

This challenge actually has two different intended solutions, one which requires using the display_menu and one which doesn't, your code is actually very close to the solution that does not require the display_menu variable.

If you remove the display_menu variable (which has a typo in it by the way, in the form of a period right after the variable name) and instead use the format method directly on the string you assign to the method variable like this:

available = "banana split;hot fudge;cherry;malted;black and white"
sundaes = available.split(';')
menu = "Our available flavors are: {} ".format(", ".join(sundaes))

Then your code will pass. As what this challenge is ultimately looking for is to have a formatted menu stored in the menu variable.

The other intended solution for this challenge looks like this:

available = "banana split;hot fudge;cherry;malted;black and white"
sundaes = available.split(';')
menu = "Our available flavors are: {} "
display_menu = ", ".join(sundaes)
menu = menu.format(display_menu)

That solution performs the same work as the other solution but splits the joining of the sundaes and the formatting of the menu into separate steps.