Variables in Python

Variables in Python are simple to create and use. Python is dynamically typed, meaning you don't need to declare variable types.

Creating Variables: Simply assign a value with the = operator.

Naming Rules:

• Must start with a letter or underscore
• Can contain letters, numbers, underscores
• Case-sensitive (name and Name are different)
• Cannot use reserved words

Naming Conventions:

• Use snake_case for variables and functions
• Use UPPER_CASE for constants
• Use PascalCase for classes
• Be descriptive: user_email instead of e

Multiple Assignment: Python allows assigning multiple variables at once.

Type Hints (Python 3.5+): Optional type annotations for better code documentation.

# Simple variable assignment
name = "Alice"
age = 30
is_student = False
height = 5.7

print(f"Name: {name}")
print(f"Age: {age}")
print(f"Student: {is_student}")
print(f"Height: {height}")

# Multiple assignment
x, y, z = 1, 2, 3
print(f"x={x}, y={y}, z={z}")

# Same value to multiple variables
a = b = c = 0
print(f"a={a}, b={b}, c={c}")

# Swapping variables (Python magic!)
x, y = y, x
print(f"After swap: x={x}, y={y}")

# Type hints (optional but recommended)
user_name: str = "Bob"
user_age: int = 25
is_active: bool = True

# Check variable type
print(f"Type of name: {type(name)}")
print(f"Type of age: {type(age)}")