How do I write a null (no-op) contextmanager in Python?

Question

Sometimes I need a dummy context manager that does nothing. It can then be used as a stand-in for a more useful, but optional, context manager. For example:

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Answer 1

Since Python 3.2, memoryview(b'') can be use as a no-op context manager. See https://docs.python.org/3/library/stdtypes.html#memoryview.release.

Pros

• No imports required

• Works on 3.2+

• Roughly twice as fast as contextlib.nullcontext

Cons

• You probably want to add a # no-op comment.