Variables & Data Types

What Is a Variable?

A variable is a named storage location for data. Create one with the assignment operator =: the name on the left, the value on the right.

• score = 95 — stores 95 in a box called "score"
• score = 100 — now the box holds 100; old value is gone
• Names can use letters, digits, and underscores but cannot start with a digit

The Four Basic Data Types

• int — whole numbers: 42, -7, 0
• float — decimal numbers: 3.14, -0.5, 2.0
• str — text in quotes: "Hello", 'Python'
• bool — only True or False

Use type(x) to see which type a variable is.