Variables and Data Types

A variable is a labeled box: you put a value in it once, then use its name anywhere you want that value. Text goes in quotation marks (a string); numbers do not. With an f-string you can drop a variable straight into a sentence, so a program can greet a player by name instead of saying the same thing every time.

• Make a variable and store a value in it with =.
• Tell the difference between text (a string) and a number.
• Use a variable inside a printed sentence with an f-string.
• Find and fix a variable that was used the wrong way.

variable

A named box that stores a value so you can use it again later.

assign

To put a value into a variable using the = sign.

integer

A whole number with no decimal point, like 10.

f-string

A sentence that starts with f, where anything inside { } is filled in from a variable.

Edit the starter code below and press Run to see it work. Use Reset starter code to go back to the original at any time.

Expected output

Player: Alex
Age: 10
Favorite game: soccer

Add a variable called score and set it to 0, then print a line like Score: 0. You will track a score exactly like this in your final game.

This should print My name is Alex, but it prints the word name instead. The variable's value is not getting filled in. What has to go around name inside an f-string?

Broken code

name = "Alex"
print(f"My name is name.")

Put curly braces around the variable so Python fills in its value:
print(f"My name is {name}.")

Add a number variable called high_score and print one sentence that uses both name and high_score, like: Alex's best score is 25.

You changed what the program says just by changing one variable. Why is that better than typing the player's name over and over in every line?

Facilitating this lesson? See the teacher & librarian guide for how to run it, common mistakes, and an offline backup activity.