useless-finally (RUF072)

Preview (since 0.15.8) · Related issues · View source

Fix is sometimes available.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for finally clauses that only contain pass or ... statements

Why is this bad?

An empty finally clause is a no-op and adds unnecessary noise. If the try statement has except or else clauses, the finally clause can simply be removed. If it's a bare try/finally, the entire try statement can be replaced with its body

Example

try:
    foo()
except Exception:
    bar()
finally:
    pass

Use instead:

try:
    foo()
except Exception:
    bar()

Example

try:
    foo()
finally:
    pass

Use instead:

foo()

See also

• [needless-else][RUF047]: Removes empty else clauses on try (and other statements). Both rules can fire on the same try statement
• [suppressible-exception][SIM105]: Rewrites try/except: pass to contextlib.suppress(). Won't apply while a finally clause is present, so RUF072 must remove it first
• [useless-try-except][TRY203]: Flags try/except that only re-raises