Variables

Creating Variables

Python uses dynamic typing, meaning you don't have to declare what type a variable is. Just assign a value and Python figures it out.

name = "Alice"
age = 25
price = 19.99
logged_in = False

Try it Yourself →

Naming Rules

Variable names must start with a letter or underscore, followed by letters, numbers, or underscores. They cannot start with a number and cannot use Python keywords.

my_var = 10
_private = 20
var2 = 30
myVariableName = 40  # camelCase works too

Try it Yourself →

Changing Values

Variables can be reassigned to different values, even different types, at any time.

x = 10
print(x)
x = "Now I'm a string"
print(x)

Try it Yourself →

Multiple Assignment

You can assign values to multiple variables in one line. This is clean and convenient.

a, b, c = 1, 2, 3
print(a)
print(b)
print(c)

Try it Yourself →

Swapping Variables

Swapping two variables is incredibly elegant in Python. No temporary variable needed.

x = 5
y = 10
x, y = y, x
print(x)
print(y)

Try it Yourself →

Variables in Strings

Use f-strings to embed variable values directly into strings. Put an f before the opening quote and use curly braces around variable names.

name = "Bob"
age = 30
message = f"{name} is {age} years old"
print(message)

Try it Yourself →

Deleting Variables

Use the del keyword to remove a variable entirely. After deletion, the variable no longer exists.

x = 100
print(x)
del x
print(x)  # This will cause an error

Try it Yourself →

🧪 Quick Quiz

Which of these is a valid variable name in Python?

← Previous Comments

Next → Data Types