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unused-async (RUF029)

Preview (since v0.4.0) · Related issues · View source

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What it does

Checks for functions declared async that do not await or otherwise use features requiring the function to be declared async.

Why is this bad?

Declaring a function async when it's not is usually a mistake, and will artificially limit the contexts where that function may be called. In some cases, labeling a function async is semantically meaningful (e.g. with the trio library).

Example

async def foo():
    bar()

Use instead:

def foo():
    bar()