Ternary Operator (if ... else)

Python does not use the C / Java ternary operator ?:.

Instead, Python uses the if ... else expression to choose one of two values.

What you'll learn

• Python’s ternary syntax (Expr1 if Test else Expr2)
• How the test picks exactly one branch
• When a ternary replaces a short if / else assignment
• That Python does not support ?:

Syntax

variable = Expr1 if TestCondition else Expr2

How it works:

• if and else are Python keywords.
• TestCondition must evaluate to True or False.
• If the test is True, Python returns Expr1.
• If the test is False, Python returns Expr2.
• Only one of the two expressions is evaluated.

Visual flow

Example 1 — Adult or Minor

age = 20

status = "adult" if age >= 18 else "minor"

print(status)

adult

Since 20 >= 18 is True, Python chooses "adult".

Example 2 — Bigger Number

a, b = 10, 3

bigger = a if a > b else b

print(bigger)

10

The expression returns the larger value.

Example 3 — Even or Odd

n = 7

parity = "even" if n % 2 == 0 else "odd"

print(parity)

odd

The modulo operator % checks whether the remainder is zero.

Example 4 — Pass or Fail

marks = 34.56

result = "pass" if marks >= 40 else "fail"

print(result)

fail

Since 34.56 is below 40, Python chooses the else expression.

Interactive playground

Move the sliders and see the ternary expressions update live.

Ternary vs traditional if/else

Both programs produce the same result.

Traditional

if age >= 18:
    status = "adult"
else:
    status = "minor"

Ternary

status = (
    "adult"
    if age >= 18
    else "minor"
)

Use the ternary form when you are choosing between two values in a single assignment.

Practice exercises

Exercise 1 — Assign "pass" or "fail" using one ternary expression.

marks = 75

result = __________

Exercise 2 — Choose the smaller of two numbers.

a = 8
b = 12

smaller = __________

Exercise 3 — Rewrite this using a ternary.

if n > 0:
    sign = "positive"
else:
    sign = "negative"

Try your answers in the playground at the bottom of this lesson.

Quick knowledge check

1. Does Python support ?:?
   No. Python uses if ... else.

2. Which expression runs when the condition is False?
   Expr2 (the else part).

3. Can the test be a logical expression?
   Yes. Any expression that evaluates to True or False can be used.

Summary

• Python’s ternary syntax is Expr1 if Test else Expr2.
• It chooses exactly one of two expressions.
• It’s ideal for short value assignments.
• Python does not support the C-style ?: operator.

Next module: String Handling — string methods, slicing, indexing, searching, replacing, and practical text-processing techniques.