Home > DeveloperSection > Forums > Does Python have a ternary conditional operator?
Chintoo Semi

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Posted on    May-11-2015 12:23 AM

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If not, is it possible to simulate one concisely using other language constructs?

Mayank Tripathi
Mayank Tripathi

Total Post:397

Posted on    May-11-2015 8:23 AM

Yes, it was added in version 2.5. The syntax is:
a if test else b
First test is evaluated, then either a or b is returned based on the Boolean value of test;
if test evaluates to True a is returned, else b is returned.

For example:

>>> 'true' if True else 'false'
>>> 'true' if False else 'false'
Keep in mind that it's frowned upon by some Pythonistas for:

The order of the arguments is different from many other languages (such as C, Ruby, Java, etc.), which may lead to bugs when people unfamiliar with Python's "surprising" behaviour (they may reverse the order).
Some find it "unwieldy", since it goes against the flow of thought; you think of the condition first and then the effects.
Stylistic reasons.
If you're having trouble remembering the order (as many seem to do), then remember that if you read it out loud, you (almost) say what you mean x = 4 if b > 8 else 9 is read out loud as  x will be 4 if b is greater than 8 otherwise 9.

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