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Variables are used to store data that can be used and modified throughout a Python program. Python is dynamically typed, meaning you don't need to specify the data type of a variable—it’s inferred at runtime based on the assigned value.

Syntax:

variable_name = value

Python uses the assignment operator = to assign values to variables.

Rules for Naming Variables

• Must start with a letter (A–Z or a–z) or an underscore _.
• The rest of the name can contain letters, digits (0–9), and underscores.
• Variable names are case-sensitive (Name and name are different).
• Avoid using Python keywords (like for, if, class) as variable names.

Good examples: name, _counter, age2, is_valid

Invalid examples: 2name, my-name, class

Let's see some examples,

num = 10
name = "Praveen"
price = 99.99
is_valid = True

Use descriptive variable names: Instead of x = 10, prefer age = 10.

Variable names should reflect their purpose.

You can reassign a variable to a different data type:

data = 5        # Initially an integer
data = "text"   # Now it's a string

This flexibility is due to dynamic typing.