Don't we already have the mock module for that ? A mowk works as a noop, will be ok with being used as a context manager and allow chaining... Either way, what would a noop function really give you compared to lambda *a, **b: None ? A be bit shorter to write. Maybe faster to run. But do you use it so much that it needs to be included ? It's not rocket science. And as a built-in, noon of the less. If it's coded it in C to gain perfs, then: - let's put it in functools, not in built-in. I often wish for partial to be built-in, but it's not. Honestly the fonctools and itertools module should be autoimported (I always do in my PYTHONSTARTUP). But no pony for us, let's not clutter the global name spaces. - provide it with it's little sister, the identity function. They almost always go hand in hand and doing the whole work of this PEP is a nice opportunity. sorted/max/min/sort and most validation callbacks have an identity function as default parameters. We would have then functools.noop and functools.identity. - provide a pure Python backport. Aternatively, just rewrite part of the mock module in C. You'll get a fast noop, with a lot of features, and as a bonus would speed up a lot of unit tests around here.