First Look at Lists

Like we said before, a list is a lot like a list that you already know about, like a grocery list:

Things To Buy
  - apples
  - oranges
  - bread 
  - milk

But in Python we would write it like this:

things_to_buy = [ 'apples','oranges','bread','milk']

The brackets, [ and ] are most often used to mean that something is a list.

There are a lot of neat things we can do with a list.

First, you can get a specific item from a list, using the [] with a number inside.

things_to_buy[1]
> oranges

Getting values out of a list like this is called "indexing".

Like most programming languages, the first item in a list is 0, not 1, so if you wanted to get apples from the list, you would write things_to_get[0]

Another important thing about lists is you can iterate them, which means 'do something repeatedly'. Here is how we would print out all of the items in the list:

Loops and lists could be very useful for our turtle programs. For instance, we could make a square with a different color on each side:

Or, we could change the angle that tina turns:

Here is a way that we could change two variables at once, using array indexes:

Now, write your own crazy program. You can copy and change the programs we've done previously.