Ternary conditional expression in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a ternary conditional expression in Python?

It is a way to write an if-else statement in one line. It chooses one value if a condition is true, and another if false.

beginner

Write the syntax of a ternary conditional expression.

value_if_true if condition else value_if_false

beginner

How does a ternary conditional expression improve code?

It makes code shorter and easier to read when choosing between two values based on a condition.

beginner

Example: What does this code print? <br>

print('Yes' if 5 > 3 else 'No')

It prints 'Yes' because 5 is greater than 3, so the condition is true.

intermediate

Can ternary conditional expressions be nested?

Yes, you can put one ternary expression inside another to check multiple conditions, but it can become hard to read.

What is the correct way to write a ternary conditional expression in Python?

A value_if_true if condition else value_if_false

B if condition then value_if_true else value_if_false

C condition ? value_if_true : value_if_false

D if condition: value_if_true else value_if_false

Python uses 'value_if_true if condition else value_if_false' syntax for ternary expressions.

What will this print? <br>

print('Even' if 4 % 2 == 0 else 'Odd')

A Odd

B Error

C Even

D 4 % 2 == 0

4 % 2 == 0 is true, so it prints 'Even'.

Which part of the ternary expression is evaluated first?

A All at the same time

B value_if_true

C value_if_false

D condition

The condition is checked first to decide which value to use.

Is this a valid ternary expression? <br>

result = 'Yes' if x > 0 else 'No'

A No

B Yes

C Only if x is defined

D Only in Python 2

This is valid Python syntax for a ternary conditional expression.

What is a downside of nesting ternary expressions?

A They can be hard to read

B They run slower

C They cause syntax errors

D They don't work in Python

Nesting ternary expressions can make code confusing and hard to understand.

Explain how a ternary conditional expression works and write a simple example.

Think of it as a short if-else in one line.

Describe when it is good to use a ternary conditional expression and when to avoid it.

Consider how easy your code is to read.