On Wed, May 18, 2016 at 1:36 AM, Devin Jeanpierre <jeanpierreda@gmail.com> wrote:

...

This is one of those things which are so easy to implement which makes you think it is probably not worth adding to the stdlib, but then again, this is something I've ended up doing and rewriting pretty often over the years. Real world example:

class DummyLock(object): def __init__(self, *args, **kwargs): pass def __enter__(self, *args, **kwargs): return self def __exit__(self, *args, **kwargs): pass

def get_lock(name, bypass_lock=False): lock_cls = DummyLock if bypass_lock else RedisLock return lock

with get_lock('foo', bypass_lock=True): ...

with contextlib.ExitStack() as exit_stack: if not bypass_lock: exit_stack.enter_context(RedisLock())

And similar.

In fact, ExitStack can itself be used as a no-op context manager, if you want.

-- Devin

I didn't think about this. So yeah, my proposal is useless. Nevermind. -- Giampaolo - http://grodola.blogspot.com

On Wed, May 18, 2016, 10:12 Ethan Furman <ethan@stoneleaf.us> wrote:

On 05/18/2016 06:16 AM, Giampaolo Rodola' wrote:

...

On Wed, May 18, 2016 at 1:36 AM, Devin Jeanpierre wrote:

...

...

with contextlib.ExitStack() as exit_stack: if not bypass_lock: exit_stack.enter_context(RedisLock())

And similar.

In fact, ExitStack can itself be used as a no-op context manager, if you want.

I didn't think about this. So yeah, my proposal is useless. Nevermind.

Not at all. It's a good use-case, and it helped introduce/remind us about ExitStack (which I suspect is a hidden gem).

So thank you all! :)

Python 3.6 also has a context manager ABC so you could also use that in 2 lines for a dummy context manager. -brett

-- ~Ethan~

_______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/

On Wed, May 18, 2016 at 1:36 AM, Devin Jeanpierre <jeanpierreda@gmail.com> wrote:

...

This is one of those things which are so easy to implement which makes you think it is probably not worth adding to the stdlib, but then again, this is something I've ended up doing and rewriting pretty often over the years. Real world example:

class DummyLock(object): def __init__(self, *args, **kwargs): pass def __enter__(self, *args, **kwargs): return self def __exit__(self, *args, **kwargs): pass

def get_lock(name, bypass_lock=False): lock_cls = DummyLock if bypass_lock else RedisLock return lock

with get_lock('foo', bypass_lock=True): ...

with contextlib.ExitStack() as exit_stack: if not bypass_lock: exit_stack.enter_context(RedisLock())

And similar.

In fact, ExitStack can itself be used as a no-op context manager, if you want.

-- Devin

I didn't think about this. So yeah, my proposal is useless. Nevermind. -- Giampaolo - http://grodola.blogspot.com

On Wed, May 18, 2016, 10:12 Ethan Furman <ethan@stoneleaf.us> wrote:

On 05/18/2016 06:16 AM, Giampaolo Rodola' wrote:

...

On Wed, May 18, 2016 at 1:36 AM, Devin Jeanpierre wrote:

...

...

with contextlib.ExitStack() as exit_stack: if not bypass_lock: exit_stack.enter_context(RedisLock())

And similar.

In fact, ExitStack can itself be used as a no-op context manager, if you want.

I didn't think about this. So yeah, my proposal is useless. Nevermind.

Not at all. It's a good use-case, and it helped introduce/remind us about ExitStack (which I suspect is a hidden gem).

So thank you all! :)

Python 3.6 also has a context manager ABC so you could also use that in 2 lines for a dummy context manager. -brett

-- ~Ethan~

_______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/