Variables are containers that store information in your programs. Understanding them is fundamental to programming.
What are Variables?
# Python variables
name = "Alice" # String
age = 25 # Integer
height = 5.6 # Float
is_student = True # Boolean
print(f"{name} is {age} years old")
Common Data Types
# Numbers
integer_num = 42
float_num = 3.14
complex_num = 2 + 3j
# Strings
text = "Hello, World!"
multiline = """This is
a multiline string"""
# Boolean
is_active = True
is_admin = False
# Lists
numbers = [1, 2, 3, 4, 5]
mixed = [1, "two", 3.0, True]
Type Conversion
# Convert between types
age_str = "25"
age_int = int(age_str)
price = 19.99
price_str = str(price)
# Check type
print(type(age_int)) #
Variable Naming Rules
# Good variable names
user_name = "Alice"
total_price = 100.50
is_logged_in = True
# Avoid
x = "Alice" # Too vague
UserName = "Bob" # Use snake_case in Python
1st_name = "Error" # Can't start with number
Good variable naming makes code readable and maintainable!