Understanding Variables and Data Types in Python

In Python, variables act as containers for data, and data types determine what can be stored and what operations are possible.

1. Variables: Data Containers

Definition: use assignment operator = to store data, e.g. name = "Alice" age = 25 height = 1.68

Naming rules: may contain letters, digits, underscores; cannot start with a digit; cannot use Python keywords; descriptive names are recommended.

Python is dynamically typed, so variable types are inferred from assigned values.

2. Data Types: Kinds of Data

Python provides several built-in data types.

Numbers: int (e.g., 10 , -5 ), float (e.g., 3.14 ), complex (e.g., 1+2j ).

String: enclosed in single or double quotes, e.g., "Hello, world!" .

Boolean: True or False .

List: ordered collection in square brackets, e.g., [1, 2, 3] or ['apple', 'banana', 'orange'] .

Tuple: ordered collection in parentheses, e.g., (1, 2, 3) .

Set: unordered collection in curly braces, e.g., {1, 2, 3} .

Dictionary: key‑value pairs in curly braces, e.g., {'name': 'Alice', 'age': 25} .

3. Type Conversion

Python offers functions to convert between types: int() , float() , str() , list() , tuple() , set() , dict() .

4. Summary

Understanding variables and data types is fundamental to Python programming; mastering them enables effective data manipulation and the creation of robust programs.