Variables and Data Types in Python

Give your data a name, and let Python remember it for you

Big Idea: A variable is a name that points to a value. You put a value into a variable once, and after that you can use the name again and again. Every value has a type — a number, some text, or a yes/no answer — and Python always knows which type it is.

By the end you will be able to:

create a variable with the = sign,
use the four core types: int, float, str, and bool,
change (reassign) what a variable holds,
check any value's type with type().

1. What is a variable?

A variable is a labelled box where Python stores a piece of information for you. You choose a name for the box, and you put a value inside it. Later, whenever you write the name, Python gives you back the value.

Analogy: Think of a jar with a sticky label. You write "sugar" on the label and pour sugar inside. Later you do not need to look in the jar — the label tells you what is there. A variable works the same way: the name is the label, and the value is what is stored.

You create a variable with the equals sign =. The name goes on the left and the value goes on the right:

name = "Ada"
age = 11
print(name)
print(age)

Output:

Ada
11

Read name = "Ada" as: "Let the name name point to the value Ada." The = here does not mean "equals" like in maths — it means "put this value into this name."

2. A picture of variables

Each variable is a name (the label) that points to a value. Every value has a type.

A name on the left points to a value on the right, and each value has a type. Here name holds text (a str), age holds a whole number (an int), and is_student holds a true/false answer (a bool).

Variables and Data Types in Python