if / else

if / else

In this tutorial, we'll choose between two paths.

Use if / else when your program should choose between two paths.

age = 16

if age >= 18:
    print("Adult ticket")
else:
    print("Child ticket")

If the condition is true, the if block runs. Otherwise, the else block runs.

Why else Is Useful

Without else, you might write two separate conditions:

if age >= 18:
    print("Adult ticket")

if age < 18:
    print("Child ticket")

This works, but else is clearer because there are exactly two possibilities.

Example: Login

password = "python123"

if password == "python123":
    print("Access granted")
else:
    print("Access denied")

Only one branch can run.

else Has No Condition

Do not write a condition after else:

else password != "python123":  # wrong

else means "anything that did not match the if".

Think of It as a Fork

An if / else is like a fork in the road. Python can go left or right, but not both.

has_homework = True

if has_homework:
    print("Do homework first")
else:
    print("Free time")

This makes it useful for clear yes/no decisions.

Practice

Create a variable called score. Print "Pass" if the score is at least 50. Otherwise print "Try again".