Variables and Data Types

What is a Variable?

A variable is a container for storing data values. In Python, you don't need to declare the type.

Creating Variables

name = "John"      # String
age = 25           # Integer
height = 1.75      # Float
is_student = True  # Boolean

Basic Data Types

Strings (str)

message = "Hello, World!"
name = 'Python'
String methods
print(message.upper())  # HELLO, WORLD!
print(len(message))    # 13

Integers (int)

count = 42
negative = -10

Floats (float)

price = 19.99
temperature = -5.5

Booleans (bool)

is_active = True
has_permission = False

Type Checking

x = 10
print(type(x))  # <class 'int'>
y = "Hello"
print(type(y))  # <class 'str'>

Type Conversion

# String to Integer
num = int("42")    # 42
Integer to String
text = str(42)     # "42"
String to Float
price = float("19.99")  # 19.99

Summary

• Variables store data
• Python has dynamic typing
• Common types: str, int, float, bool

Next Lesson

In the next lesson, you'll learn about operators in Python.