Conditional expression
- Python course
- Beginner
- Lesson 40/116
- 4 min
Learn single-line conditionals with x if cond else y.
Conditional expression
A conditional expression (or ternary) writes if/else in one line:
age = 20
status = "Adult" if age >= 18 else "Child"
print(status)The form is: value_if_true if condition else value_if_false. This is handy for simple assignments; complex logic prefers normal if/else.
Using conditional expressions
The conditional expression is especially useful for variable assignment:
score = 75
result = "Passed" if score >= 50 else "Failed"
print(result)The same logic can be written with if/else but this is shorter. Never nest conditional expressions; it gets unreadable.
Practice Print a conditional expression
Assign score = 75. Assign result = "Passed" if score >= 50 else "Failed". Print print(result).
Starter code
# Conditional expressionSample solution
score = 75
result = "Passed" if score >= 50 else "Failed"
print(result)Expected output
Passed
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 If age is 20, what does "Adult" if age >= 18 else "Child" give?
- Error
- Child
- Adult Correct answer
- None
Explanation: 20 >= 18 is True, the first value is taken.
2 Complete the conditional expression
status = "Adult" ____ age >= 18 else "Child"status = "Adult" if age >= 18 else "Child"Explanation: if separates the condition in a conditional expression.
3 Match the conditional expression parts
| Term | Meaning |
|---|---|
value if |
When true |
condition |
After if |
else |
When false |
one line |
Conditional expression advantage |