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:

ctx_         


        

Answer 1

A simple solution for Python 3.6 and below, including 2.7:

from contextlib import contextmanager

@contextmanager
def nullcontext(enter_result=None):
    yield enter_result

Since Python 3.7 you should use the provided contextlib.nullcontext instead.