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Sometimes code needs to assign (or otherwise use) a value that depends on some condition. The naive approach is to use explicit branching, which in Python would look like: if some_condition(): ...
#1: Initial revision
by
Karl Knechtel
·
2023-12-01T23:12:00Z (12 months ago)
Does Python have a "ternary operator" (conditional evaluation operator like "?:" in other languages)?
Sometimes code needs to assign (or otherwise use) a value that depends on some condition. The naive approach is to use explicit branching, which in Python would look like:
```
if some_condition():
a_variable = condition_value
else:
a_variable = not_condition_value
```
However, this seems needlessly verbose, and is not DRY - the assignment syntax is repeated.
Many other popular languages support some way to write an [expression](https://software.codidact.com/posts/289228) that evaluates to either of two stated options, depending on the condition. Typically this uses what is often called a "ternary conditional operator" or just "the ternary operator"[^1], commonly written using `?` and `:` symbols - so it looks like:
```
a_variable = some_condition() ? condition_value : not_condition_value
```
Generally this operator is *short-circuiting*: i.e., if `condition_value` and/or `not_condition_value` are more complex expressions, only the necessary one is evaluated according to the `some_condition()` result.
**Does Python have any syntax like this?**
[^1]: Here, "ternary" simply means that there are three operands; but this operator is often referred to as "the" ternary operator because it is typically the only one in the language with that property.