4.7 Conditional expressions

Learning objectives

By the end of this section you should be able to

• Identify the components of a conditional expression.
• Create a conditional expression.

Conditional expressions

A conditional expression (also known as a "ternary operator") is a simplified, single-line version of an if-else statement.

Conditional expression template:

    expression_if_true if condition else expression_if_false

A conditional expression is evaluated by first checking the condition. If condition is true, expression_if_true is evaluated, and the result is the resulting value of the conditional expression. Else, expression_if_false is evaluated, and the result is the resulting value of the conditional expression.

A variable can be assigned with a conditional expression. Ex: Finding the max of two numbers can be calculated with max_num = y if x < y else x

Note: Conditional expressions have the lowest precedence of all Python operations.

if x%2 == 0:
  response = 'even'
else:
  response = 'odd'

result = x + offset if x < 100 else x - offset

min_num = x if x < y else min_num = y

if x < 50:
  result = True
else:
  result = False

total = fee + 10 if hours > 12 else 2