View Discussion Improve Article Save Article View Discussion Improve Article Save Article Ternary operators are also known as conditional expressions are operators that evaluate something based on a condition being true or false. It was added to Python in version 2.5. Syntax : Output:
It simply allows testing a condition in a
single line replacing the multiline if-else making the code compact.
[on_true] if [expression] else [on_false]
Python
a, b = 10, 20min = a if a < b else bprint[min]10
Python
a, b = 10, 20print[ [b, a] [a < b] ]
print[{True: a, False: b} [a < b]]
print[[lambda: b, lambda: a][a < b][]]
Output:
10 10 10
Time Complexity: O[1]
Auxiliary Space: O[1]
- Ternary operator can be written as nested if-else:
Python
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"]
Time Complexity: O[1]
Auxiliary Space: O[1]
The above approach can be written as:
Python
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
Time Complexity: O[1]
Auxiliary Space: O[1]
- To use print function in ternary operator be like:-
Example: Find the Larger number among 2 using ternary operator in python3
Python3
a=5
b=7
print[a,"is greater"] if [a>b] else
print[b,"is Greater"]
Output:
7 is Greater
Time Complexity: O[1]
Auxiliary Space: O[1]
Important Points:
- First the given condition is evaluated [a < b], then either a or b is returned based on the Boolean value returned by the condition
- Order of the arguments in the operator is different from other languages like C/C++ [See C/C++ ternary operators].
- Conditional expressions have the lowest priority amongst all Python operations.
Method used prior to 2.5 when the ternary operator was not present
In an expression like the one given below, the interpreter checks for the expression if this is true then on_true is evaluated, else the on_false is evaluated.
Syntax :
'''When condition becomes true, expression [on_false] is not executed and value of "True and [on_true]" is returned. Else value of "False or [on_false]" is returned. Note that "True and x" is equal to x. And "False or x" is equal to x. ''' [expression] and [on_true] or [on_false]
Example :
Python
a, b =
10, 20
min = a < b and a or b
print[min]
Output:
10
Time Complexity: O[1]
Auxiliary Space: O[1]
Note : The only drawback of this method is that on_true must not be zero or False. If this happens on_false will be evaluated always. The reason for that is if the expression is true, the interpreter will check for the on_true, if that will be zero or false, that will force the interpreter to check for on_false to give the final result of the whole expression.
This article is contributed by Mayank Rawat and improved by Shubham Bansal. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to . See your article appearing on the GeeksforGeeks main page and help other
Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.