Ternary Operator in Python

In this article, you’ll learn how to use the ternary operator in Python. The ternary operator in Python is simply a shorter way of writing an if and if…else statement. We’ll see its syntax along with some practical examples.

Python Ternary Operator and its Benefits

The Python ternary operator determines if a condition is true or false and then returns the appropriate value in accordance with the result. The ternary operator is useful in cases where we need to assign a value to a variable based on a simple condition, and we want to keep our code more concise — all in just one line of code. It’s particularly handy when you want to avoid writing multiple lines for a simple if-else situation.

Syntax of Ternary Operator in Python

Syntax: [on_true] if [expression] else [on_false]

expression: conditional_expression | lambda_expr

Simple Method to Use Ternary Operator

In this example, we are comparing and finding the minimum number by using the ternary operator. The expression min is used to print a or b based on the given condition. For example, if a is less than b then the output is a, if a is not less than b then the output is b.

Python3

# Program to demonstrate conditional operator
a, b = 10, 20

# Copy value of a in min if a < b else copy b
min = a if a < b else b

print(min)

Output

10

Ternary Operator Examples

Here we will see the different example to use Python Ternary Operator:

• Ternary Operator in Python If-Else
• Python Ternary Operator using Tuples
• Python Ternary Operator using Dictionary
• Python Ternary Operator using Lambda
• Print in if Ternary Operator
• Limitations of Python Ternary Operator

Ternary Operator in Python If-Else

Example: Using Native way

Python program to demonstrate nested ternary operator. In this example, we have used simple if-else without using ternary operator.

Python3

a, b = 10, 20

if a != b:
    if a > b:
        print("a is greater than b")
    else:
        print("b is greater than a")
else:
    print("Both a and b are equal")

Output

b is greater than a

Example: Using Ternary Operator

In this example, we are using a nested if-else to demonstrate ternary operator. If a and b are equal then we will print a and b are equal and else if a>b then we will print a is greater than b otherwise b is greater than a.

Python3

# Python program to demonstrate nested ternary operator
a, b = 10, 20

print ("Both a and b are equal" if a == b else "a is greater than b"
        if a > b else "b is greater than a")

Output

b is greater than a

Python Ternary Operator using Tuples

In this example, we are using tuples to demonstrate ternary operator. We are using tuple for selecting an item and if [a<b] is true it return 1, so element with 1 index will print else if [a<b] is false it return 0, so element with 0 index will print.

Python3

# Python program to demonstrate ternary operator
a, b = 10, 20

print( (b, a) [a < b] )

Output:

10

Python Ternary Operator using Dictionary

In this example, we are using Dictionary to demonstrate ternary operator. We are using tuple for selecting an item and if [a<b] is true it return 1, so element with 1 index will print else if [a<b] is false it return 0, so element with 0 index will print.

Python3

# Python program to demonstrate ternary operator
a, b = 10, 20

print({True: a, False: b} [a < b])

Output

10

Python Ternary Operator using Lambda

In this example, we are using Lambda to demonstrate ternary operator. We are using tuple for selecting an item and if [a<b] is true it return 1, so element with 1 index will print else if [a<b] is false it return 0, so element with 0 index will print.

Python3

# Python program to demonstrate ternary operator
a, b = 10, 20

print((lambda: b, lambda: a)[a < b]())

Output

10

Print in if Ternary Operator

In this example, we are finding the larger number among two numbers using ternary operator in python3.

Python3

a=5
b=7

# [statement_on_True] if [condition] else [statement_on_false]
print(a,"is greater") if (a>b) else print(b,"is Greater")

Output

7 is Greater

Limitations of Python Ternary Operator

Python ternary is used to write concise conditional statements but it too have some limitations.

• Readability: Ternary operator can make simple conditional expressions more concise, it can also reduce the readability of your code, especially if the condition and the expressions are complex.
• Potential for Error: Incorrect placement of parentheses, missing colons, or incorrect order of expressions can lead to syntax errors that might be harder to spot.
• Debugging: When debugging, it might be harder to inspect the values of variables involved in a complex ternary expression.
• Maintenance and Extensibility: Complex ternary expressions might become harder to maintain and extend especially when the codebase grows.
• Can’t use assignment statements: Each operand of the Python ternary operator is an expression, not a statement, that means we can’t use assignment statements inside any of them. Otherwise, the program will throw an error.

Example:

Python3

3 if True else x=6

Output:

File "Solution.py", line 1
    3 if True else x=6
    ^
SyntaxError: can't assign to conditional expression