Lists

Lists can be used to group different values together - it’s just a collection of things.

You can make a list in Python by putting different things in a box of brackets [] separated by commas:

# command Python to make a list and store it in my_list
my_list = ['pizza', 'fries', 3, -2.5, 'donuts']

# command Python to print my_list
print(my_list)

['pizza', 'fries', 3, -2.5, 'donuts']

Now let’s make a list of fruit and save it to the variable fruit. Have your list include apple, banana, grape, and any other fruit you want!

# command Python to make a list of fruit including apple, banana, and grape
fruit = ['apple','banana','grape']
# command Python to print the list of fruit
print(fruit)

['apple', 'banana', 'grape']

You can also see how many things there are in your list using len:

# command Python to find the length of my_list
len(my_list)

Let’s find the length of the fruit list:

# command Python to find the length of your fruit list
len(fruit)

To add lists together, all you have to do is use the + operator.

# command python to add my_list and fruit
my_list + fruit

['pizza', 'fries', 3, -2.5, 'donuts', 'apple', 'banana', 'grape']

You can also make a list that includes variables:

# assign the value 1 to the variable a
a = 1
# assign the value 2 to the variable b
b = 2
# make a list including values and variables and save it to the variable numbers
numbers = [0, a, b, a+b]
# print the numbers list
print(numbers)

[0, 1, 2, 3]

To add a value to a list, you can use .append():

# append 4 to the list numbers
numbers.append(4)
# print numbers
print(numbers)

[0, 1, 2, 3, 4]

Let’s add mango to our fruit list:

# add mango to fruit list
fruit.append('mango')
# print fruit
print(fruit)

['apple', 'banana', 'grape', 'mango']

You just learned how to: * Make a list * Find the length of a list * Add lists together * Add things to a list

Now it’s time to practice what you learned!