@ 3:30 I don't get the "" when joining the code back together

To understand statements like this I like to go to from the most inner part to the outer part. Let's start by considering

rainbow = ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'v', 'i', 'o', 'l', 'e', 't']

Then, the slice rainbow[-6:] will return the last 6 items on the list. We will effectively have:

>>> rainbow[-6:]
>>> ['v', 'i', 'o', 'l', 'e', 't']

Next, we have the join method used at "".join(rainbow[-6:]). The official documentation shows str.join(iterable). This means the join method is called on a string str and we must also pass an iterable object. The string specified is used between each of items that belong to the iterable object. By passing an empty string "" we are saying: we don't want anything between the items. Also important is to keep in mind that the return will be a new string.

>>> "".join(rainbow[-6:])
>>> "violet"

Finally, the brackets []. Remember that in Python you can create a list in one of the following ways:

>>> x = list()
>>> x
[]

or

>>> x = []
>>> x
[]

Here we use the second method, but instead of creating an empty list, we are passing a single element to the list as its very first element.

>>> x = ["violet"]
>>> x
['violet']

The very end is just a substitution of the last 6 elements in the rainbow list for this single element.

Hope this helps.

Good luck

Dear Marie,

might you check the command seperate.

rainbow = ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'v', 'i', 'o', 'l', 'e', 't']
print(rainbow[-6:])
['v', 'i', 'o', 'l', 'e', 't']
print("".join(rainbow[-6:]))
violet

rainbow[-6:] are all six last item in the list. and he "overwrite" all this a List with one string (join of the last 6) the [] are importend around the command.

Try

rainbow[-8:] = ["".join(rainbow[-6:])]
['red', 'orange', 'yellow', 'green', 'violet']

You just "overwrite" than more because of the -8

I hope a bit clearer. Greetings Julian

The empty string "" is what will be joining the elements. If he replaced "" with "." the result would have been v.i.o.l.e.t.