I'm having issues reassigning menu and using .format()

Hi there!

You're on the right track - you've correctly assigned display_menu's value, but in order to use it in .format, it needs to be before the menu line, like this:

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

Then, you can add your .format() after the menu string, to replace the {} with the contents of display_menu:

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

In case you're curious, the challenge also mentions being able to do the join and format in the same line with menu - that looks like this:

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

With .format, you basically have a string value that includes curly braces {}. When you add .format to that string, the parentheses contain whatever you want to replace those curly braces with. If you have more than one set of curly braces in the string, you would put a value for each one in the parentheses, like this:

example = "{} is learning to program in {}".format("Katie", "Python")  #"Katie is learning to program in Python"

Hope this helps!