Ternary Operator in Python

Ternary operator perform conditional checks and assign values or execute expressions in a single line. It is also known as a conditional expression because it evaluates a condition and returns one value if the condition is True and another if it is False.

Let’s start with an example to determine whether a number is even or odd:

Odd

Explanation:

• n % 2 == 0: checks if n is divisible by 2 (even).
• "Even" if n % 2 == 0 else "Odd": ternary operator assigns "Even" if the condition is True, otherwise "Odd".

Ways to Use Ternary Operator

1. Nested If-Else

Ternary operator can also be used in Python nested if-else statement. We can nest ternary operators to evaluate multiple conditions in a single line.

Syntax:

value_if_true if condition else value_if_false

Negative

Explanation:

• First, it checks if num > 0. If True, it returns "Positive".
• If False, it checks if num < 0. If True, it returns "Negative".
• If both conditions fail, it defaults to "Zero".

2. Tuple

Ternary operator can also be written by using Python tuples. The tuple indexing method is another way to select between two values using a boolean index. Unlike the ternary operator, both tuple elements are evaluated before the selection is made.

Syntax:

(condition_is_false, condition_is_true)[condition]

Odd

Explanation: The condition num % 2 == 0 evaluates to False (index 0), so it selects "Odd".

3. Dictionary

A dictionary can be used to map conditions to values, providing a way to use a ternary operator with more complex conditions.

Syntax:

condition_dict = {True: value_if_true, False: value_if_false}

20

Explanation: This uses a dictionary where the key is True or False based on the condition a > b. The corresponding value (a or b) is then selected.

4. Using Ternary Operator Inside Lambda Function

Lambdas can be used in conjunction with the ternary operator for inline conditional logic.

Syntax:

lambda x: value_if_true if condition else value_if_false

20

Explanation: This defines an anonymous function (lambda) that takes two arguments and returns the larger one using the ternary operator. It is then called with a and b.

5. Print Function

The ternary operator can also be directly used with the Python print statement.

Syntax:

print(value_if_true if condition else value_if_false)

b is greater

Explanation: This checks if a is greater than b. If true, it prints "a is greater"; otherwise, it prints "b is greater".

Limitations of Python Ternary Operator

While the ternary operator is concise, it should be used with caution:

• It can reduce readability if overused or used in complex conditions.
• It's limited to simple, single-line expressions.

Related Articles

• Different Ways of Using Inline if (ternary operator) in Python
• Conditional Statements in Python