When we want to add multiple items to a list, we can use +
to combine two lists (this is also known as concatenation).
Below, we have a list of items sold at a bakery called items_sold
:
items_sold = ["cake", "cookie", "bread"]
Suppose the bakery wants to start selling "biscuit"
and "tart"
:
items_sold_new = items_sold + ["biscuit", "tart"] print(items_sold_new)
Would output:
['cake', 'cookie', 'bread', 'biscuit', 'tart']
In this example, we created a new variable, items_sold_new
, which contained both the original items sold, and the new items. We can inspect the original items_sold
and see that it did not change:
print(items_sold)
Would output:
['cake', 'cookie', 'bread']
We can only use +
with other lists.
If we type in this code:
my_list = [1, 2, 3] my_list + 4
we will get the following error:
TypeError: can only concatenate list (not "int") to list
If we want to add a single element using +
, we have to put it into a list with brackets ([]
):
my_list + [4]
Let’s use +
to practice combining two lists!
Instructions
Jiho is updating a list of orders
. He just received orders for "lilac"
and "iris"
.
Create a list called new_orders
that contains our new orders.
Use +
to create a new list called orders_combined
that combines orders
with new_orders
.
Remove the #
and whitespace in front of the list broken_prices
. If you run this code, you’ll get an error:
TypeError: can only concatenate list (not "int") to list
Fix the command by inserting brackets ([
and ]
) so that it will run without errors.