Sentry Answers>Python>

Python equivalent of a ternary operator: if-then-else in one line

Python equivalent of a ternary operator: if-then-else in one line

David Y.

—

The Problem

Many C-like languages include a ternary operator, which is used for expressing simple if-then-else statements in a single line. It usually looks something like this:

Click to Copy
int x = b == true ? 1 : 0 // if b == true, x = 1; else x = 0

Is there a way to do this in Python?

The Solution

Yes, Python supports inline conditional assignments using a form of the ternary operator, usually called a conditional expression. The syntax is as follows:

Click to Copy
x = 1 if b == True else 0

# or

x = 1 if b else 0

In this code, if b is true, x will be set to 1, otherwise x will be set to 0.

Similarly, simple if statements can be written on a single line:

Click to Copy
if b == True: x = 1

However, this syntax is unusual and does not allow for the inclusion of an else clause on the same line. Conditional expressions should be preferred for simple assignments, and more complex code should be split across multiple lines.

Click to Copy
if b == True:
    x = 1
    print("b is True and x is 1")
else:
    x = 0
    print("b is False and x is 0")
  • Sentry BlogPython Performance Testing: A Comprehensive Guide
  • Syntax.fmListen to the Syntax Podcast
  • Sentry BlogLogging in Python: A Developer’s Guide
  • CodecovPython - Codecov
  • Syntax.fm logo
    Listen to the Syntax Podcast

    Tasty treats for web developers brought to you by Sentry. Get tips and tricks from Wes Bos and Scott Tolinski.

    SEE EPISODES

Considered “not bad” by 4 million developers and more than 100,000 organizations worldwide, Sentry provides code-level observability to many of the world’s best-known companies like Disney, Peloton, Cloudflare, Eventbrite, Slack, Supercell, and Rockstar Games. Each month we process billions of exceptions from the most popular products on the internet.

learn more about sentryjoin our discord
© 2024 • Sentry is a registered Trademark of Functional Software, Inc.